Don’t Trust the Odds (Ratio)

The title of this post is inspired by Scott Alexander’s Never Tell Me The Odds (Ratio). The goal of this post is to explain the meanings of (commonly-heard) metrics that indicate the “odds” of something (either directly or indirectly).

Just because these terms are commonly-heard does not mean they are commonly-understood. The odds are that most people don’t understand the numbers related to the odds – and misinterpret how big the odds really are.

Let’s take an example, borrowed from Scott Alexander:

Suppose you run a drug trial. In your control group of 1000 patients, 300 get better on their own. In your experimental group of 1000 patients (where you give them the drug), 600 get better.

The relative risk of recovery from the drug = probability of recovering from the drug in the experimental group ÷ probability of recovering on one’s own in the control group = (600 / 1000) ÷ (300 / 1000) = 60% ÷ 30% = 2.0.

The odds from recovering from the drug in the experimental group = probability of recovering ÷ probability of not recovering = 600 ÷ (1000 – 600) = 3/2. Likewise, the odds from recovering on your own in the control group = 300 ÷ (1000 – 300) = 3/7.

The odds ratio = odds of recovering from the drug ÷ odds of recovering on one’s own = (3/2) ÷ (3/7) = 3.5.

The Cohen’s d effect size takes the difference in the average of two groups (x1 – x2) and divides it by the standard deviation (s):

cohen's d effect size
cohen's d calculation

(Formula screenshots taken from this post on effect size.) Cohen’s d for the example above = (0.6 – 0.3) / 0.474341 = 0.6. I have used this standard deviation calculator and this Cohen’s d calculator. Note that Scott Alexander’s result is a little bit different at 0.7.

To recap, for the example above, we got the following results:

  • Relative risk (drug vs. self-recovery) = 2.0
  • Odds ratio (drug vs. self-recovery) = 3.5
  • Cohen’s d effect size = 0.6

The numbers lie on a wide range from 0.6 to 3.5 – and depends on which one is reported, and in what fashion, it could bias up (or down) the reader’s perception on how effective the drug is (vs. self-recovery). As Scott Alexander puts it:

The moral of the story is that (to me) odds ratios sound bigger than they really are, and effect sizes sound smaller, so you should be really careful comparing two studies that report their results differently.

May the odds be forever in your favor! 😉

[Book Review] The Art of Gathering

My ratings of the book
Likelihood to recommend: 3.5/5
Educational value: 4/5
Engaging plot: 3/5
Clear & concise writing: 3/5
Suitable for: anyone interested in how to host better gatherings, be it a birthday party, a family dinner, or a business meeting

Me: “I am reading a book called The Art of Gathering – it’s about tips on how to be a better host of gatherings.”

Response: “I like how you are reading about gatherings when we can’t have gatherings during social distancing. :)” Fair point – this may not be a good time to host a gathering, nevertheless it doesn’t hurt to think about how to become a better host. The learnings from the book will become especially handy when we resume normal social activities (and fingers crossed the situation would improve soon).

Before digging into the key takeaways, general comments on the book – I gave this book 3.5 stars out of 5:

  • What I like is the insights on gatherings – the book is less about what to do at gatherings (though there is a fair share of that) and more about how to think about gatherings (a mindset shift). This is not the typical logistical advice you would expect (e.g., how to arrange seats or dinner recipes). Instead, Priya Parker tells us how to re-imagine our roles as a host and the meanings of a gathering. This book reads like a combo of instructional manual + philosophy – that’s worth a 4 stars on educational value.
  • What I don’t enjoy as much is the narration style – some examples shared in the book feels a bit too wordy and could be slimmed down. For this reason, I find myself flipping through some chapters where I feel I have captured the main points, yet the examples shared are too detailed for my taste. Hence only a 3-star rating on plot & style.

And now to key takeaways from the book:

1/ Figuring out the real reason that matters is halfway towards a successful gathering. Importantly, a category is NOT a purpose, e.g., the purpose of a birthday party is NOT “to celebrate my birthday. A better but bland purpose would be “to mark the year,” and even better purposes could be along the lines of “to surround myself with the people who bring out the best in me,” “to set some goals for the year ahead with people who will help me stay accountable,” “to take a personal risk/do something that scares me.”

2/ Gathering that please everyone are rarely exciting – great gatherings are not afraid of alienating, which is not the same as being alienating. It is about taking a stand with a purpose of the gathering that stands out; it is about saying “no” to someone who want to join the gang; it is about enforcing rules to honor the purpose of the gathering and not succumbing to so-called etiquette.

(Some purposes) fail at the test for a meaningful reason for coming together: Does it stick its neck out a little bit? Does it take a stand? Is it willing to unsettle some of the guests (or maybe the host)? Does it refuse to be everything to everyone?

A good gathering purpose should also be disputable. If you say the purpose of your wedding is to celebrate love, you may bring a smile to people’s faces, but you aren’t really committing to anything, because who would dispute that purpose? … A disputable purpose, on the other hand, begins to be a decision filter. If you commit to a purpose of your wedding as a ceremonial repayment of your parents … that is disputable, and it will immediately help you make choices. That one remaining seat will go to your parents’ long-lost friend, not your estranged college buddy.

3/ A good host is never a chill host who sits back and lets guests organize themselves. I love how Priya Parker puts it: “Gathering well isn’t a chill activity. If you want chill, visit the Arctic.” Or in the words of Isaiah Berlin: “Freedom for the wolves has often meant death to the sheep.

“The chill approach to hosting is all too often about hosts attempting to wriggle out of the burden of hosting. In gatherings, once your guests have chosen to come into your kingdom, they want to be governed – gently, respectfully, and well. When you fail to govern, you may be elevating how you want them to perceive you over how you want the gathering to go for them. Often, chill is you caring about you masquerading (instead of) you caring about them.”

“Behind the ethic of chill hosting lies a simple fallacy: Hosts assume that leaving guests alone means that the guests will be left alone, when in fact they will be left to one another. Many hosts I work with seem to imagine that by refusing to exert any power in their gathering, they create a power-free gathering. What they fail to realize is that this pulling-back, far from purging a gathering of power, creates a vacuum that others can fill. These others are likely to exercise power in a manner inconsistent with your gathering’s prupose, and exercise it over people who signed up to be at your – the hosts’s – mercy, but definitely didn’t sign up to be at the mercy of your drunk uncle.”

4/ Hosting a gathering is not a democratic activity, so don’t be afraid of being the boss if you are the host. Be assertive in introducing your guests to each other a lot. Be assertive in seating guests next to people who are from different walks of life yet still complementary. Be assertive in setting your own rules, e.g., break up two friends who are talking with themselves in the corner and encourage them to mingle with everyone else.

5/ A gathering starts when your guests first hear about it, and don’t waste the time from then until the date of the gathering to prime your guests for the event. Priya Parker calls this “pregame window” a chance to shape the guests’ journey into the gathering – it is about priming the guests to get them in the right mood & mindset before the event, so that they could exhibit the behavior you would like.

The pregame should sow in guests any special behaviors you want to blossom right at the outset. If you are planning a corporate brainstorming session and you’re going to be counting on your employees’ creativity, think about how you might prime them to be bold and imaginative from the beginning. Perhaps by sending them an article on unleashing your wildest ideas a few days beforehand. If, for example, you are planning a session on mentorship in your firm, and you need people to show up with their guards down, send an email out ahead of time that includes real, heartfelt testimonials from three senior leaders sharing personal, specific examples of the transformative power that a mentor had on them.

In my own work with organizations, I almost always send out a digital ‘workbook’ to participants to fill out and return to me ahead of the gathering. I design each workbook afresh depending on the purpose of the gathering and what I hope to get guests to think about in advance. The workbooks consist of six to ten questions for participants to answer…The workbooks aren’t so different from a college application in that sense … they also help the person think through the things they value before they arrive. I then design the day based on what I see in their answers. I also weave quotes from their workbooks into my opening remarks at the convening.

6/ Quit starting or ending with logistics, such as where you should go next. It is extremely anti-climatic.

“I’m speaking, in short, of every gathering whose opening moments are governed by the thought: ‘Let’s first get some business out of the way.'”

“Just as you don’t open a gathering with logistics, you should never end a gathering with logistics, and that include sthank-yous. I am not suggesting that you cannot thank people. I simply mean that you shouldn’t thakn them as the last thing you do when gathering. Here’s a simple solution: do it as the second-to-last thing.”

“Goldman is a much-beloved teacher and singer-songwriter…To close (his classes) he strums the first note of the final song, his version of the last call, triggering the expectation of a closing in the kids, and then he pauses and makes announcements while still holding the note: Please turn in your check to me if you haven’t already. No classes next week. Someone left their jacket. He technically does these logistics between the first and second note of the final song. Once he’s finished with the logistics, he resumes the goodbye song. It’s subtle but quietly brilliant.”

7/ A soft close tactic, if done well, gives some guests the freedom to leave if they wish while lets other guests who want to stay feel welcome to linger around. Priya Parker shares a tip of inviting guests to the living room for a nightcap as a soft close for her house gatherings.

“The trouble for the host is that, for every person who is tired or checking out, there are presumably others who look as if they could keep going for hours. One of the most interesting – and divisive – dilemmas in hosting is what to do in this situation.”

“Once I can see the conversation petering out after dessert (at a home gathering), I pause, thank everyone for a beautiful evening, then suggest we move to the living room to have a nightcap. I give the guests who are tired the opportunity to leave, but both my husband and I emphasize that we’d rather everyone stay.”

“That invitation to the living room is a soft close; in a sense, it’s the equivalent of the last call. You can ask for the check, so to speak, or you can order another round. Those who are tired can leave without appearing rude, and those who want to stay can stay. The party, relocated and trimmed, resumes.”

And to heed my own advice, I should close this post with a thoughtful closing – at least somewhat thoughtful. I would like to share with you what Priya Parker wrote in the introduction of the book: there are no pre-requisites to being a good gatherer. No, you don’t have to be talkative, you don’t need to have a fancy venue, and you don’t need to hide a dozen jokes in your sleeves to entertain your guests. The magic recipe is some deliberate thought into why you are gathering, which identities of you the gathering is enforcing, and what spirit you are bringing into the gathering – it is likely to go well (or better than you imagined) if you have “the curiosity, willingness, and generosity of spirit to try.

[Book Review] The Ride of a Lifetime: Lessons Learned from 15 Years as CEO of the Walt Disney Company

My ratings of the book
Likelihood to recommend: 5/5
Educational value: 4/5
Engaging plot: 5/5
Clear & concise writing: 5/5
Suitable for: everyone, especially those interested in management & business

The Ride of a Lifetime: Lessons Learned from 15 Years as CEO of the Walt Disney Company is the memoir of Robert Iger, named as the 2019 businessperson of the year by Time magazine. Iger is well-known for revitalizing Disney with key initiatives such as the acquisition of Pixar & Marvel, and the launch of streaming services. This book is an absolute enjoyment to read – I finished it within one day.

For those who are short on time and want to get straight to the “talking points”, Roger has summarized the key takeaways in Appendix – Lessons to Lead By. I quote some of my favorites below:

“To tell great stories, you need great talent.”

“I talk a lot about ‘the relentless pursuit of perfection’…It’s not about perfectionism at all costs. It’s about creating an environment in which people refuse to accept mediocrity. It’s about pushing back against the urge to say that ‘good enough’ is good enough.”

“Don’t start negatively, and don’t start small. People will often focus on little details as a way of masking a lack of any clear, coherent, big thoughts. If you start petty, you seem petty.”

“Don’t let ambition get ahead of opportunity. By fixating on a future job or project, you become impatient with where you are. You don’t tend enough to the responsibilities you do have, and so ambition can become counterproductive.”

“If something doesn’t feel right to you, it won’t be right for you.”

When hiring, try to surround yourself with people who are good in addition to being good at what they do. Genuine decency – an instinct for fairness and openness and mutual respect – is a rarer commodity in business than it should be.

Some other takeaways from the book:

1/ Great leaders value ability over experience. This is not to say that experience is not important, but to highlight that if it comes down to placing your bet on one of the two, you should “bet on brains”.

“Tom and Dan were the perfect bosses in this regard. They would talk about valuing ability more than experience, and they believed in putting people in roles that required more of them than they knew they had in them. It wasn’t that experience wasn’t important, but they ‘bet on brains.'”

2/ A dysfunctional leadership between senior management hurts the morale of the entire company, making the staff confused, afraid, or both. It rarely ends up well.

“When the two people at the top of a company have a dysfunctional relationship, there’s no way that the rest of the company beneath them can be functional. It’s like having two parents who fight all the time.”

3/ Respecting people’s time is underrated – how you deal with time is one of the things that immediately solidifies your reputation (or breaks it). People remember the seemingly small things.

“Once, he took a call, in my office, from President Clinton, talking with him for forty-five minutes while I sat outside. A call from Tom Cruise interrupted another meeting.”

“Meeting after meeting was either canceled, rescheduled, or abbreviated, and soon every top executive at Disney was whispering behind his back about what a disaster he was. Managing your own time and respecting others’ time is one of the most vital things to do as a manager.”

4/ Micromanagement not only frustrates your employees, but could make you look petty and narrow-minded as a leader.

“Michael was proud of his micromanagement, but in expressing his pride, and reminding people of the details he was focused on, he could be perceived as being petty and small-minded. I once watched him give an interview in the lobby of a hotel and say to the reporter, ‘You see those lamps over there? I chose them.’ It’s a bad look for a CEO.”

5/ Don’t forget people who have helped you, and don’t step on them to get your own way. I respect how Iger tried to not look better at the expense of Michael, Disney’s CEO before him, who had a bad reputation and was blamed for Disney’s troubles.

“I respected Michael and was grateful for the opportunities he’d given me. I’d also been COO of the company for five years, and it would have been hypocritical, transparently so, to lay all of the blame on someone else. Mostly, though, it just wouldn’t have been right to make myself look better at Michael’s expense. I vowed to myself not to do that.”

6/ A big question to ask yourself is: who do you want to be remembered as? What is a defining feature of your identity? For George Lucas, his identity and values are largely defined by the Star Wars series – and it is touching to see how much that one thing matters to him and gives his life meaning.

“He (George Lucas) said something else that I kept in mind in every subsequent onversation we had: ‘Whe nI die, the first line of my obituary is going to read ‘Star Wars creator George Lucas…’ It was so much a part of who he was, which ofcouse I knew, but having him look into my eyes and say it like that underscored the most important factor in these conversations.”

7/ Doing what’s right as a CEO doesn’t necessarily mean doing what’s financially right. Doing what’s right means literally what it says: doing what’s right. Kudos to Iger’s decision to terminate a high-profile employee after her inappropriate Tweet.

“‘We have to do what’s right. Not what’s politically correct, and not what’s commercially correct. Just what’s right. If any of our employees tweeted what she tweeted, they’d be immediately terminated.’ I told them (the management) to feel free to push back or tell me I was crazy (to fire her), but no one did.”

“It was an easy decision (to let her go), really. I never asked what the financial repercurssions would be, and didn’t care. In moments like that, you have to look past whatever the commercial losses are and be guided, again, by the simple rule that there’s nothing more important than the quality and integrity of your people and your product. Everything depends on upholding that principle.”

In general, I find Iger’s tone to be matter-of-the-fact without much self-promotion (of himself or the company). I appreciate how he points out what he sees as strengths and weaknesses of people whom he has worked with, including his former managers or mentors.

There are some things that I think would be good to include in the book:

A/ The one business decision that Iger made, which I was not sure about, was passing the opportunity to acquire Twitter. Iger said it did not feel right, and he was worried about the (potential) liability to manage and / or moderate an open platform where anyone could post anything. It would be interesting to see what Disney would have made out of Twitter – at least I would have liked Iger to share more about what he and Disney’s Board & management initially planned to do with Twitter.

B/ I would have wanted Iger to talk more about what he felt were missed opportunities or mistakes on his own part. I felt the book largely focused on what he did right – and while he narrated these stories in a fairly neutral way (and I believe he does deserve credit where it is due), I would have liked to see his candid self-assessment on what he did wrong.

C/ One thing that the book didn’t touch upon too much is how to manage an amusement park the scale of Disney. Iger mentioned he learnt many things from his predecessors on the various aspects of design & management. It would be really cool to know what are the details that Disney management pays attention to.

That being said, the book overall has not disappointed, and could be finished in half a day. Do consider giving it a try.

[Book Review] Humble Pi: When Math Goes Wrong in the Real World

My ratings of the book
Likelihood to recommend: 5/5
Educational value: 5/5
Engaging plot: 5/5
Clear & concise writing: 5/5
Suitable for: everyone

Humble Pi is a witty & funny book that could let anyone (re)discover their love for mathematics! Overall, Matt Parker’s book is an appetizing combo of mathematics and comedy – if you want to learn mathematics while having tons of fun, this is one of the best books to start with, regardless of your background or fluency in maths.

Beyond making maths digestibly fun (and funnily digestible), another highlight of the book is how to think about thinking. In other words, the philosophy of thinking – such as how to be rational and how to prevent errors.

I particularly enjoyed the “Swiss cheese” model in thinking about errors: think about each error like a hole in a slice of cheese. And horrible sh*t (disaster) happens when somehow the holes are lined up together and the error falls through slices of cheeses, and lands in the pot of catastrophe. More often than not, a catastrophic consequence is the accumulation of a few errors – seemingly minor errors if we look at them alone – but when added together could bring explosive effects. What this means is instead of focusing too much on achieving 0 errors (which is desirable yet almost always impossible), what is more practical is to focus on improving error-detection that spots an error early – patch the first hole in the first slice of cheese, so that it does not trickle down into the remaining slices.

P.S. I’ve mentioned the Swiss cheese model in a post about premature optimization and other topics in software engineering.

I would also highly recommend checking out Matt Parker’s YouTube videos: his talks at Google and the Numberphile channel, which features bite-sized videos by various mathematicians on everyday-maths and has 3M+ subscribers to date (April 12th, 2020).

Matt Parker – Talks at Google: “Things to Make and Do in the Fourth Dimension”
Matt Parker – Talks at Google: “The Greatest Maths Mistakes”

Below I quote some parts of the book that I personally find insightful:

1/ We are used to going from theory to application, though sometimes the reverse happens: the application comes first, and then we discover the underlying theory afterwards. We should not let the joy of discovering the application over-shadow the need to fully understand the theory behind – otherwise, using the tool without really understanding its risks could hit us in the foot.

There is a common theme in human progress. We make things beyond what we understand, as we always have done. Steam engines worked before we had a theory of thermodynamics; vaccines were developed before we knew how the immune system works; aircraft continue to fly to this day, despite the many gaps in our understanding of aerodynamics. When theory lags behind application, there will always be mathematical surprises lying in wait. The important thing is that we learn from these inevitable mistakes and don’t repeat them.

2/ Don’t underestimate how little attention the public & institutions could pay to math – and what is most frustrating is not the mistakes themselves (which could be absurdly hilarious), but the lack of respect for mathematical facts or a pursuit of truth.

Matt Parker wrote to the UK government after he discovered that the geometric shape of the football was wrongly painted on signs in the UK (unlike the white hexagons, the black shapes on the ball’s surface should be pentagons instead of hexagons). However, the official response from the UK Department for Transport was: “Changing the design to show accurate geometry is not appropriate in this context.” Matt Parker clearly did not think too highly of the response he got:

They (the Department of Transport) rejected my request. With a rather dismissive response! They claimed that (1) the correct geometry would be so subtle that it would ‘not be taken in by most drivers’ and (2) it would be so distracting to drivers that it would ‘increase the risk of an incident.’ And I felt that they hadn’t even read the petition properly. Despite my asking for only new signs to be changed, they ended their reply with: ‘Additionally, the public funding required to change every football sign nationally would place an unreasonable financial burden on local authorities.’ So the signs remain incorrect. But at least now I have a framed letter from the UK government saying that they don’t think accurate math is important and they don’t believe street signs should have to follow the laws of geometry.

3/ While (most rational) people agree that 1 + 1 = 2, people don’t always agree on how the same number should be interpreted. A number ceases to be objective when subjective narratives are at play, hence we should not let our guard down and think an argument is “logical” just because numbers are used.

“It seems that, if the Trump administration couldn’t change the ACA (Affordable Care Act) itself, it was going to try to change how it was interpreted. It’s like trying to adhere to the conditions of a court order by changing your dog’s name to Probation officer.”

“[T]he Trump administration wanted to allow insurance companies to charge their older customers up to 3.49 times as much as younger people, using the argument that 3.49 rounds down to 3. […] They might as well have crossed out thirteen of the twenty-seven constitutional amendments and claimed nothing had changed, provided you rounded to the nearest whole constitution.”

“If there are enough numbers being rounded a tiny amount, even though each individual rounding may be too small to notice, there can be a sizeable cumulative result. The term ‘salami slicing’ is used to refer to a system by which something is gradually removed one tiny unnoticeable piece at a time. Each slice taken off a salami sausage can be so thin that the salami does not look any different, so, repeated enough times, a decent chunk of sausage can be subtly sequestered.”

4/ Precision and accuracy on two concepts with nuanced differences, and it is important to not mix the two. Precision is “the level of details given“, while accuracy is “how true something is“.

5/ Be ware of the word: average. Whenever you hear someone talk about averages, emind yourself of this commentary on the census from the Australian Bureau of Statistics: “While the description of the average Australian may sound quite typical, the fact that no one meets all these criteria shows that the notion of the ‘average’ masks considerable (and growing) diversity in Australia.” I would also add that the notion of the “average” masks how the average person is likely to overrate the concept of averages.

After the 2011 census, the Australian Bureau of Statistics published who the average Australian was: a thirty-seven year old woman who, among other things, ‘lives with her husband and two children…in a house with three bedrooms and two cars in a suburb of one of Australia’s capital cities.’ And then they discovered that she does not exist. They scoured all the records and no one person matched all the criteria to be truly average.

6/ Correlation does not mean causation. Just because two things have a high chance of happening at the same time does not mean one caused another. For example, I don’t think the number of math PhDs has any causal relationships with how much cheese people eat.

For the record, in the US the number of people awarded math PhDs also has an above 90 percent correlation over ten years or more with: uranium stored at nuclear-power plants, money spent on pets, total revenue generated by skiing facilities, and per capita consumption of cheese.

7/ Finally, this is one of my favorite quotes of the book on what mathematics is: “Mathematicians aren’t people who find math easy; they’re people who enjoy how hard it is.

I hope this book will rekindle your love for mathematics – or help you find it if you have never fallen in love with it in the first place.

Are reciprocal ratings the cure or the curse?

You take a Uber ride. You get off the car, open your Uber app, and leaves the driver a 4.0 / 5.0 rating. As you walk away from the car, the driver pulls out her app, and gives you a 5.0 / 5.0 rating. This is an example of reciprocal ratings, i.e., where both parties get to rate each other.

There are many examples of reciprocal ratings, especially in areas where the experience is co-created and / or shared by both parties (albeit could be in different ways). For example, on Airbnb, the guest(s) get to rate the host(s) and vice versa. In debate competitions, the adjudicators score the speakers and the speakers often get a chance to rate the adjudicators in return based on the justification of their decisions and the quality of their feedback.

The question I’d like to discuss in this post is: do reciprocal ratings bring net benefits or net harm?

The Case For Reciprocal Ratings: Fairness & Incentives to Perform

Starting from principles, it seems fair to let both sides rate each other, especially if both sides share responsibility in an experience and / or are impacted by the other side’s actions. For example, the holistic Uber ride experience is affected by both the driver’s performance (e.g., cleanliness of vehicle) and the user’s behavior (e.g., arriving on time).

I really like the concept of The Wittgenstein’s Ruler, which Nassim Nicholas Taleb (the author of “Black Swan”) talked about in a Tweet:

It is worth repeating: “When you use a ruler to measure the table, you are also using the table to measure the ruler.” Sometimes, the best measurement of how good a ruler is is not an external judge, but the tables that are measured by itself.

brown ruler with stand

If we look at practical consequences, reciprocal ratings may help both parties become more accountable for their behavior and / or decisions. In the example of a debate competition, for example, letting debaters rate adjudicators in return incentives the adjudicators to: (a) be more responsible in reaching a decision, and (b) be more detailed & elaborate in explaining their decision. Just as an adjudicator’s feedback could help debaters improve, so does a debater’s feedback let an adjudicator learn how to better judge a debate. Taking a step back, this type of benefit is not unique to reciprocal ratings, but to ratings in general: when people know that their performance is being measured (and that measurement is linked to some carrots or sticks), they are more likely to put in more effort. It is all about incentives. Economics 101.

You could say that reciprocal ratings make the interests of both parties more intertwined with each other – because debaters have a chance to rate adjudicators, it is now in both the debater and the adjudicators’ best interests to let debaters receive well thought-through feedback after a debate round. Reciprocal ratings put everyone “in the same boat” in a way.

two people shaking hands

The Case Against Reciprocal Ratings: Inflated Ratings?

But sometimes you could go from two parties being close to each other to two parties being too close to each other. Making the interests of both parties interrelated provides incentives to cooperate, as well as incentives to cheat. For example, if debater feedback for adjudicators were submitted using their real names in a debate competition, then one could argue some debaters may inflate their score for an adjudicator for fear of retaliation by that adjudicator (assuming the debaters have a significant chance of running into the same adjudicator in a future round).

There are real-world examples where people are asked to leave comments under their real name – Airbnb guest reviews, for example, are published under the guests’ real names & profile pictures. This helps to increase the perceived legitimacy and authenticity of the reviews in the eyes of interested people checking out the property’s profile page.

Assuming that (a) hosts get to rate guests in return and (b) hosts get to see the guests’ ratings & comments, then one possible scenario may happen: a guest inflates the rating for his / her host out of fear that if he / she gives the host the low rating, the host would retaliate with a low (or even lower) rating in return. The problems is symmetrical, as in one could argue that the host also has an incentive to inflate his / her ratings of the guest for the exact same reasons.

Assuming the ratings are indeed inflated, would that break the whole rating system?

Before we dive into this question, let us first look at the bigger picture: why do ratings matter in the first place? How are ratings used by a platform like Airbnb? It is worth pointing out that what matters more is the relative ranking rather than the absolute score. It is the differential rather than the absolute value that holds the key. For example, Airbnb uses relative ranking of host property to decide the ranking of search results for properties that match a user’s search criteria; similarly, Uber uses driver ratings to prioritize ride assignment.

With that established, let’s come back to the inflated ratings problem. For simplicity, let us study one side of the problem, i.e., let us assume Airbnb guests inflate their ratings of their hosts. What happens then? (Note the other side of the problem, i.e., hosts inflating their ratings of the guests, should follow a similar thought process as below.)

Let’s break down the problem into two possible scenarios:

[Scenario A] Rating inflation is a generic problem, i.e., the majority of guests inflate their ratings of hosts, or what the defenders of fairness would call “the whole system is rigged”.

There are two sub-scenarios:

(A1) If the majority of guests inflate their ratings by a similar absolute amount, e.g., +1 star higher.
=> Verdict: In this sub-scenario, rating inflation does not impact the effectiveness of the search ranking algorithm. This is because if the score of every host gets bumped up by +1 star, then their ranking does not change, i.e., a potential guest searching for a property would still see a list of hosts ranked in the same order;

(A2) If the majority of guests inflate their ratings to a certain level, e.g., if everyone gives their hosts 4 stars (regardless of whether they think they only deserve 2 stars or 3 stars), then things get a bit tricky. You could say in this case, the really stellar hosts will still get their 5-star ratings and rise to the top of the competition – they would still be prioritized by Airbnb’s search ranking algorithm. However, in this case, one could no longer differentiate between the mediocre hosts (e.g., those who deserve 3 stars) from the really bad ones (e.g., those who deserve 2 stars), as their scores are all inflated to 4 stars across the board.
=> Verdict: In this sub-scenario, rating inflation does make the ranking algorithm less effective – it is still able to break down hosts into groups based on their ratings (stellar hosts vs. other hosts), and prioritize the groups in search results. However, the grouping becomes less granular. One could argue the practical results may not be too bad – as the super-stellar hosts that get 5 stars would still come up at the top of search results for hosts. If we assume that the top search results are also the most-clicked-on results by potential guests, then it is likely that the final choice of the guests are not distorted that much. This kind of reasoning reminds me of the Pareto principle (80/20 rule) – applied in this context, 20% of your search results (the top ones) may generate 80% of your revenue. If this holds, then as long as the top search results are not distorted, then the search ranking algorithm has served its purpose.

Image result for 80/20 rule

[Scenario B] Rating inflation is an isolated problem, i.e., only a very small % of the guests inflate their ratings of the hosts. The majority of the guests rate their hosts honestly.

The answer here is quite straightforward: this would have very limited impact on the search ranking results. Perhaps a small number of hosts would get their ratings bumped up a bit, but the majority of the hosts are ranked fairly. By definition of an “isolated problem” above, this is not a problem that causes massive headaches for the average user – and hence not worth losing your sleep over.

The Verdict on Reciprocal Ratings

Having reciprocal ratings is probably a good idea – based on the very limited analysis thus far. Caveats: 1) I have (very lazily) only considered inflated ratings as a down side to reciprocal ratings, though there could be many more, and 2) the designs of the ratings could affect the incentives of players – for example, is one side asked to rate another side first? Are the ratings published in real time? Are the ratings published anonymously? Etc.,

All in all, I find reciprocal ratings design – and ratings in general – to be a fascinating real-world game-theory topic. The next time I take a Uber ride and rate a driver, I’ll certainly “think twice” before giving that 5 stars.

person holding black iphone 5

Live Deliberately, Not Conditionally: On Carpe Diem

I went to the woods because I wanted to live deliberately […] I wanted to live deep and suck out all the marrow of life.

Henry David Thoreau (quoted in the movie “Dead Poets Society”)

carpe diem
quam minimum credula postero
* * *
Seize the Day
Trust Tomorrow as Little as You May

“Carpe diem. Seize the day, boys. Make your lives extraordinary.” Such was the advice Mr. John Keating gave his students in the movie Dead Poets Society. Along with this, he passed along an answer to the meaning of life: “That you are here – that life exists, and identity; that the powerful play (of life) goes on and you may contribute a verse.”

But how do we seize the day? What is happiness, the one thing that we seem to be dreaming so much of and capturing so little of?

Carpe Diem = Reject Living Conditionally

We don’t want to be unconditionally happy. I’m ready to be happy provided I have this and that and the other thing. But this is really to say to our friend or to our God or to anyone, ‘You are my happiness. If I don’t get you, I refuse to be happy.
– Awareness: The Perils and Opportunities of Reality

Happiness, for most people on most days, rarely comes with “no strings attached.” Happiness is the product of an “if…then…” clause, which is typically phrased in one of two ways:

  • If I have [X], then I will be happy.
  • If I do not have [X], then I cannot be happy.

I think the above is more accurately stated as:

  • If I have [X], then I will be happy for a limited time only (until I see a better alternative to [X] called [Y]).
  • If I do not have [X], then I choose to be unhappy.

In his eye-opening book Awareness: The Perils and Opportunities of Reality, Anthony de Mello shares an FAQ he gets: “Nobody loves me; how, then, can I be happy?” Anthony replies with this witty question: “You mean you never have any moments when you forget you’re not loved and you let go and are happy?”

Image result for Awareness: The Perils and Opportunities of Reality

“Until everyone started getting transistors, they were perfectly happy without one. That’s the way it is with you. Until somebody told you you wouldn’t be happy unless you were loved, you were perfectly happy. You can become happy not being loved, not being desired by or attractive to someone. You become happy by contact with reality. That’s what brings happiness, a moment-by-moment contact with reality.”
– Awareness: The Perils and Opportunities of Reality

In the words of Naval Ravikant: “That’s the fundamental delusion – that there is something out there that will make you happy forever.” Once we drop this illusion and come into contact with reality, that is when we are better positioned to Seize the Day.

Carpe Diem = Embrace Living Deliberately

A common rejection to carpe diem is that we should be “rational being” and not be driven by “irrational whims.”

John Keating’s quote in Dead Poets Society in some ways answers this concern: “There’s a time for daring and there’s a time for caution, and a wise man understands which is called for.” Rather than being the slave of our desires & wants, we should be their Captain.

Such is living deliberately – choosing what preferences to satisfy with a deliberate purpose to stay true to ourselves, and to stay honorable to our values. In the words of Ayn Rand: “Happiness is that state of consciousness which proceeds from the achievement of one’s values.” Living deliberately means being able and willing to choose actions that not only satisfy our pleasure, but also match our values.

Image result for There's a time for daring and there's a time for caution, and a wise man understands which is called for.

To all friends and readers – Carpe Diem. Make Life Extraordinary. Let us all remember to better seize the day as the footsteps of a brand new year draws near. May we all be better present for 2020 ahead.

“I am a crazy idiot, and I am cool with that.” Kudos to (healthy doses of) self-deprecating humor

Self-deprecating humor is underrated. When inhaled (in healthy doses), it works magic and immediately drives away all the frustration, worries and negative emotions.

There are many versions of the Manifesto of Self-Deprecating Humor. Here are a few that I like:

1/ Everyone is an idiot

Everyone is an idiot, not just the people with low SAT scores. THe only differences among us is that we’re idiots about different things at different times. No matter how smart you are, you spend much of your day being an idiot.

– Scott Adams, The Dilbert Principle

If we proudly identify ourselves (& everyone in the world) as idiots, then it is very natural to transit into a peaceful mood – suddenly we are no longer angry with that “moron” whose “stupidity lowered the IQ of the whole street.”

In the words of Scott Adams, “If you can come to peace with the fact that you’re surrounded by idiots, you’ll realize that resistance is futile, your tension will dissipate, and you can sit back and have a good laugh at the expense of others.

2/ Everyone is crazy

I love Awareness: The Perils and Opportunities of Reality by A. De Mello. Highly recommended by Tim Ferriss – a book on what “waking up” means.

A key takeaway from the book: realize we are all crazy. Everyone. Not just Professor Snape. Not just your ex who rings you at 3 AM. Not just your neighbor who suspects you are a cat-turned-witch.

Everyone is crazy. Whether they are as smart as Einstein, as dumb as [insert-the-name-of-someone-you-hate], they are all crazy. And you are crazy too.

Do you know one sign that you’ve woken up? It’s when you are asking yourself, ‘Am I crazy, or are all of them crazy?’ It really is. Because we are crazy. The whole world is crazy. Certifiable lunatics! The only reason we’re not locked up in an institution is that there are so many of us.

– A. De Mello, Awareness: The Perils and Opportunities of Reality

We are all monkeys that are easily manipulated

I press a button and you’re up; I press another button and you’re down. And you like that. How many people do you know who are unaffected by praise or blame? That isn’t human, we say. Human means that you have to be a little monkey, so everyone can twist your tail, and you do whatever you ought to be doing. But is that human?

A. De Mello, Awareness: The Perils and Opportunities of Reality

Let’s read that last part again: “Human means that you have to be a little monkey, so everyone can twist your tail, and you do whatever you ought to be doing.”

Do you feel good when people say you are good?

Do you feel bad when people say you are bad?

I do – many times. I bet you do too. And that’s what makes us manipulable monkeys – there are certain “buttons” that we seem to be conditioned to respond to.

The defense De Mello recommends is this:

“You go ahead and be yourself, that’s all right, but I’ll protect myself, I’ll be myself.”
* * *
I won’t allow you to manipulate me. I’ll live my life; I’ll go my own way; I’ll keep myself free to think my thoughts, to follow my inclinations and tastes.

A. De Mello, Awareness: The Perils and Opportunities of Reality

The not-so-sexy solution to the problem is: Just Be Yourself. Be Your Crazy & Idiotic Self. Be proud of your craziness and idiocy that relapses once in a while and will continue to relapse for the rest of your life. And that is okay – that realization makes us easily drop demands we have on others, because how could we expect everyone to act rationally all the time, when we cannot do the same ourselves?

So let’s chant the self-deprecating-humor mantra to close: “I am a crazy idiot, and I am cool with that.”

I hope you are too.

Choose or risk forever surrendering your peace – Why Having Your Own Philosophy Matters

Speak now, or forever hold your peace” could be traced back to the Christian wedding ceremony, where the audience is given the last chance to voice any objections to the marriage. It is one example where it is important to have an opinion and defend it – or else risk surrendering it forever.

Similarly, when it comes to philosophy of life, everyone needs to have their own version of philosophy – we either choose how to think for ourselves now, or risk forever surrendering our peace by letting others choose for us, by letitng others decide what is right or wrong, what makes life worth living, what our course of action should be.

To Swim or Not to Swim, That is the Question

That IS the question: whether to float with the tide, or to swim for a goal. It is a choice we must all make consciously or unconsciously at one time in our lives.

Hunter S. Thompson’s Letter on Finding Your Purpose and Living a Meaningful Life

Almost everything we do is a choice between floating (i.e., default to the curent of others) vs. swimming (i.e., chart our own course). Only those with a philosophy of life of their own knows how to swim.

Thomson goes on to say: “And it seems almost ridiculous to say that a man MUST function in a pattern of his own choosing; for to let another man define your own goals is to give up one of the most meaningful aspects of life— the definitive act of will which makes a man an individual.

Taking a step back, not everyone realizes we are in the water in the first place. There is a joke of two fish swimming along and running into a third fish, which asks them: “Morning, how’s the water?” The two fish stare at each other and ask blankly: “What the hell is water?”

David Foster Wallace’s comment in his 2005 commencement speech “This is Water” is very to the point:

“The point of the fish story is merely that the most obvious, important realities are often the ones that are hardest to see and talk about. […] in the day to day trenches of adult existence, banal platitudes can have a life or death importance.”

Wallace goes on to say “the single most pervasive cliché in the commencement speech genre” is that “a liberal arts education is not so much about filling you up with knowledge as it is about ‘teaching you how to think.’

Twenty years after my own graduation, I have come gradually to understand that the liberal arts cliché about teaching you how to think is actually shorthand for a much deeper, more serious idea: learning how to think really means learning how to exercise some control over how and what you think. It means being conscious and aware enough to choose what you pay attention to and to choose how you construct meaning from experience. Because if you cannot exercise this kind of choice in adult life, you will be totally hosed. Think of the old cliché about ‘the mind being an excellent servant but a terrible master.’

Ayn Rand on Why Having A Philosophy Of Your Own Matters

As Ayn Rand puts it, everyone has a philosophy of some sorts: “As a human being, you have no choice about the fact that you need a philosophy. Your only choice is whether you define your philosophy by a conscious, rational, disciplined process of thought and scrupulously logical deliberation.

In other words, we all have a philosophy whether we consciously acknowledge it or not – the choice we have is whether this philosophy is chosen by ourselves thanks to our mind (“swim”), or chosen for us dictated by others (“float”):

The men who are not interested in philosophy absorb its principles from the cultural atmosphere around them—from schools, colleges, books, magazines, newspapers, movies, television, etc. Who sets the tone of a culture? A small handful of men: the philosophers. Others follow their lead, either by conviction or by default.”

How to Decide Where to Swim Towards?

Choosing a philosophy for ourselves could be harder than it seems. Charlie Munger shares his tip on how to avoid the trap of unclear thinking & decision-making:

I have what I call an ‘iron prescription’ that helps me keep sane when I drift toward preferring one intense ideology over another. I feel that I’m not entitled to have an opinion unless I can state the arguments against my position better than the people who are in opposition. I think that I’m qualified to speak only when I’ve reached that state.

Charlie Munger

Hunter Thompson shares his advice on how to lead a meaningful life:

A man has to BE something; he has to matter.
As I see it then, the formula runs something like this: a man must choose a path which will let his ABILITIES function at maximum efficiency toward the gratification of his DESIRES. […] In short, he has not dedicated his life to reaching a pre-defined goal, but he has rather chosen a way of life he KNOWS he will enjoy. The goal is absolutely secondary: it is the functioning toward the goal which is important.”

The World ALWAYS Makes Sense

When was the last time you felt like this boy:

(Disclaimer: I like square roots. I think maths is awesome.)

We have all had our fair share of saying / hearing the likes of:

  • “This doesn’t make sense.”
  • “I wish it made more sense.”
  • “How can I make sense of this thing?”
  • “Nothing makes sense!”
  • ….you get the idea

Here is the good news: (A) The world always makes sense. As every good news feels lonely without its companion – the bad news – bear in mind that when you feel something doesn’t make sense, (B) what is not making sense is your model of the world.

Note to logical hygiene freaks: Some of you may immediately challenge – “Hey but what you said does not make sense! If both statements (A) & (B) hold, then the logical conclusion is (C) your “model of the world” is exterior to (not part of) “the world,” which is self-defeating if the world encompasses every living organism – your brain (and by extension, your mind) is part of the world.

Fair enough, 5 bonus points if that matters. And now we move on. And yes, I am saying regardless of whether the challenge makes sense or not, I am moving on as if it doesn’t. 🙂

If statements (A) and (B) sound abstract, you may find this analogy below helpful:

Here is what a cylinder looks like in different contexts:

  • 3D environment: cylinder
  • 2D projection: square / circle depending on the angle of projection

In the 2D world, which is a one-dimensional reduction of the cylinder, we could say that both the square & the circle are “true ‘slices’ of the reality of the cylinder; neither alone give a clear sense of the higher dimensional shape’s reality.” This is inevitable because “they are reducing the reality (without realizing it) to a view that simply can not adequately contain it.

How should we deal with the seemingly contradiction of square vs. circle? I think Daniel Schmachtenberger nailed it:

The problem of course is in the reductionism. There is no 2D slice of a 3D object that gives a real sense of what it is. Neither is any 2D negotiation of slices going to yield something in 3D. The cylinder is not somewhere between the two reductionistic views: 50% circle, 50% rectangle… It is 100% of both descriptions…which are only mutually exclusive and paradoxical if they are trying to be reconciled in the same plane, which is the essential mistake.
In the higher dimensional reality the object (cylinder) actually lives in, the simultaneous full truth of both partial descriptions (square & circle) is obvious and non-paradoxical…as is the seamless way they fit together as parts of a congruent whole.

Daniel Schmachtenberger, Higher Dimensional Thinking, the End of Paradox, and a More Adequate Understanding of Reality

Blog recommendation: I highly recommend Daniel’s blog Civilization Emerging for some mind-opening posts. In addition, check out his recommended readings on various topics.

To conclude: when we think the world doesn’t make sense, what doesn’t make sense is our interpretation of it – it could that we are futilely trying to find a 2D explanation that 100% fits a 3D problem, which means we inevitably end up with (i) a paradox that cannot be reconciled and / or (ii) a puzzle that cannot be explained, and (iii) a messed-up mind. Note that I used “and / or” vs. “and” – because (iii) is a “gift” that you are 100% guaranteed to get.

To end with a sentence that I hope makes sense: It’s never too late to make sense of how we are making sense of the world, which always makes sense when analyzed under the model that makes the best sense.

Secret to Longevity: Make Frequent “Quantum Jumps” to New Reality-Matrices

Disclaimers: (1) This post may mess with your mind, and (2) this post is intended to mess up your mind. #smirk#

Cultural conditioning, in every tribe, is a process of gradually narrowing your tunnel-reality. The way to stay young (comparatively; until the longevity pill is discovered) is to make a quantum jump every so often and land yourself in a new reality-matrix.

Robert Anton Wilson, Cosmic Trigger I: Final Secret of the Illuminati

“Reality” is Messed Up!

I mean the word “reality” itself is a messed-up word that is misleading about the reality it intends to convey (pun intended). 😉

In the crazy – and/or – magical – and/or – daring – and/or -neurotic – and/or -creepy- and/or – [insert-your-adjective(s) of choice] book (more like mind-bender), Cosmic Trigger I: Final Secret of the Illuminati, Robert Wilson thinks it is a misleading pity that “reality” is (a) a noun, and (b) in singular form.

“Reality” (more like realities) is / are “always plural and mutable“. Forget about a single source of truth. Forget about realizing reality. We could each construct our own ‘reality,’ but there is no such thing as THE REALITY that we could all arrive at.

Consider the “conventional wisdom” that seeing is believing:

“We perceive an orange as really orange, whereas it is actually blue, the orange light being the light bouncing off the real fruit. And, everywhere we look, we imagine solid objects, but science only finds a web of dancing energy.”

“The orange has the orange color” is a statement that describes your mental projection (identified image, conscious recognition) of “a web of dancing energy”:

“All of our perceptions have gone through myriads of neural processes in the brain before they appear to our consciousness. At the point of conscious recognition, the identified image is organized into a three-dimensional hologram which we project outside ourselves and call ‘reality’.”

The next time you hear yourself say: “The reality is…” Catch yourself. It is more accurate to say: “My model of the reality is…” The map is not the territory. The menu is not the meal. The model of reality is not the reality itself – if it even exists in the first place. This line of thinking is known as the Copenhagen Interpretation, or “model agnosticism”.

As an extension of the “model agnoticism,” there are two principles / rules of the game:

  1. The principle of neurological relativism by Timothy Leary: “No two people ever report exactly the same signals.
  2. The way to “double your practical intelligence” according to Robert Wilson: “Try to receive as many signals as possible from other humans, however wrong-headed their reality-map may seem” and avoid the “habit of screening out all human signals not immediately compatible with our own favorite reality-map.”

Reality (and all behavior) is a Giant Game?

According to the Morgenstern-von Neumann game theoretic model, “most human transactions can be analyzed mathematically by treating them as if they were games”, and personality could be analyzed as “a group process defined by rules of interpersonal politics”.

If you are wondering WTH that really means, consider the application of model by Timothy Leary, a psychologic best known for his exploration of psychedelics:

What are the players actually doing in space-time? […] What are the rules of the game? How many strikes before you’re out? Who makes the rules? Who can change the rules? These are the important questions.

Timothy Leary

Leary developed a seven-dimensional game model to analyze all behavior, with respect to:

  1. Roles being played;
  2. Rules tacitly accepted (by all payers);
  3. Strategies for winning;
  4. Goals of the game;
  5. Language of the game (and the semantic world-view implied);
  6. Characteristic space-time locations, and
  7. Characteristic movements in space-time.

As Leary said: “If you can’t describe those seven dimensions of a group’s behavior, you don’t understand their game. Most so-called ‘neurosis’ is best analyzed as somebody programmed to play football wandering around in a baseball field. If he thinks football is the only game in the universe, the other players will seem perverse or crazy to him; if they think baseball is the only game, he’ll seem crazy to them.”

As of such, in the eyes of Leary, most psychological terminology are “pre-scientific” and “vague.” He thinks it makes much more sense to analyze it like a game.

Is Discordianism (the Cosmic Giggle Factor) the Best Way to View Reality?

So far it sounds a bit depressing – “reality” is / are messed up, “reality” is a complicated game with seven dimensions, and “THE reality” may be forever beyond our grasp (if it even exists).

You may feel your mind exploding. What is the best way to view reality?

One approach is Discordianism, invented by Thornley & Gregory Hill in the 1950s, dubbed as the first true “true religion.” Discordianism worships the Greek goddess of chaos & confusion, Eris:

Discordianism is the religion or belief in which chaos is thought to be as important as order…in contrast with most religions, which idealize harmony and order.

Discordia Wiki
“Sacred Chao” – the symbol of Discordianism

In the words of Wilson, the first law of Discordianism is: “Convictions cause convicts.” In other words, “whatever you believe imprisons you,” “”belief is the death of intelligence,” and “the more certitude one assumes, the less there is to think about.”

Some view Discordianism as a parody religion, but Wilson makes the case to take it more seriously:

“I saw Discordianism as the Cosmic Giggle Factor, introducing so many alternative paranoias that everybody could pick a favorite, if they were inclined that way. I also hoped that some less gullible souls, overwhelmed by this embarrassment of riches, might see through the whole paranoia game and decide to mutate to a wider, funnier, more hopeful reality-map.”

Wilson hopes Discordianism would persuade more people to “make a quantum jump” to a “new reality-matrix”, different from the narrow tunnel-reality that culture has conditioned them into.

To sum up, the biggest takeaway from Wilson’s book is probably this:

Our models of “reality” are very small and tidy, the universe of experience is huge and untidy, and no model can ever include all the huge untidiness perceived by uncensored consciousness.

Robert Anton Wilson, Cosmic Trigger I: Final Secret of the Illuminati

What are things that blew your mind about how you view reality? Leave a comment or write to me at!