Two Sides of the Same Model

Yesterday’s post and today’s post are really talking about the same thing (or the same model, to be a little bit pedantic), but it’s a little bit like that story about the blind men and the elephant.

Which model? This one:

The Solow–Swan model or exogenous growth model is an economic model of long-run economic growth. It attempts to explain long-run economic growth by looking at capital accumulation, labor or population growth, and increases in productivity largely driven by technological progress.

https://en.wikipedia.org/wiki/Solow%E2%80%93Swan_model

Ask yourself a simple question: which countries in the world today are likely to see reasonably rapid growth over the course of the next three decades or so?

As a person whose job it is to teach people introductory economics, I’m not as interested in your answer as much as I am in your framework for coming up with your answer. No matter whether you say India, or China or Nigeria or Indonesia or any other nation of your choice – why do you choose the set of answers that you do? What is your model for doing so?

And whatever model you come up with, and whatever specification of the model you deem most appropriate, it should have the following ingredients:

  1. People. No country can grow if its labor-force isn’t growing. Duh.
  2. Capital. More machines, more output. Also duh.
  3. Technological progress. It’s not just people and machines, but it is how efficiently you use them, and the quality of your ideas about how to use them. Not so duh, and often underrated.
  4. Quality of education. A close cousin of the third point, if you think about it. Definitely not duh, and a pet passion (and peeve!) of mine.
  5. Quality of institutions. See this video for an explanation. The very opposite of duh, and massively underrated almost always.

So: my pick for a country that is to grow rapidly over the course of the next three decades would have to tick most, if not all of these boxes. And yesterday’s post was about understanding the point that where India is concerned, her rate of growth is somewhat likely to be constrained by her inability to dispense quality education efficiently and at scale, and by the quality of her institutions. We also need to ramp up our capital stock (our infrastructure). Or put another way, if we try to maximize growth without getting these things right, it’s going to create more problems for us down the road.


A warm welcome to Shruti Rajagopalan, who launched her Substack yesterday. Her first post, and indeed her general focus on her entire blog, is about paying more attention to India. Bad puns that are actually good is an underappreciated art form, so a high five is in order for the name of the blog too! (Update: Mihir Mahajan very kindly pointed out that this is actually a song. I obviously hadn’t heard it before, and in case you haven’t either, here you go. Thanks, Mihir!)

Her post is about a lot of things about why (and how) one should pay more attention to India. But the first two sections of her essay are what I want to focus upon here:

  1. “India’s population will peak in 2065. Compare this with China, where the population will peak next year.”
  2. “Smartphone penetration in India since 2010”

If Gulzar Natarajan yesterday spoke about capital, the quality of education and the quality of institutions (2,4 and 5 from my list above), think of Shruti’s post as a discussion about people and technological progress (1 and 3 from my list above). And a great way to learn about the Solow Model is to first learn about it, and then think about India in the context of the Solow model. Which, of course, is what these two posts are trying to do.

Take, in other words, the model out of the diagrams and the math, and apply it to the world around you. And a great place to begin is here, in India!


Shruti’s post is worth reading (and worth using as a teching tool) because it also speaks about labor mobility (or the lack of it), and capital mobility also. And soft power too, if you want even more! So do give it a read, and bookmark her blog, or add it to your RSS reader.

P.S. The very last section of her blogpost speaks about how to get started on learning more about India. I’d add at least two points to her list, the first because it is a passion of mine. If you want to learn more about any country, learn more about its food. Which ingredients are used at what time of the year, and why? What are the popular dishes in different parts of that country, and why? What do food taboos and food habits have to do with the culture, the sociology and the religions of that country? It’s a great way to learn more about different countries, and especially true for India. If you haven’t seen the light yet, and are therefore not as besotted with food as I am, consider music instead.

Or dance, if you like. Or textiles. But pick an entry point that you like, and read/see/travel optimizing for that entry point. But most of all, haffun – that’s the whole point, after all.

And for anybody who’s struggling with the Solow Model, trust you me, you can have fun while slogging through it all. This post is the proof!

Do border regions have better food?

Do border regions have better food? What exactly counts as a border region? The parts of the United States near Canada? The best food in Italy is not obviously at the (rather skimpy) borders. China and India might be the best food countries in the world, but because they are so large most of their cuisine is not “border cuisine.” So I say no.

https://marginalrevolution.com/marginalrevolution/2022/11/requests-from-benedikt.html

As always, read the whole post – and in particular, the Wikipedia link to James Steuart (not a typo). But given my deep love of all things gastronomical, I wanted to expand on this point a bit.

  1. Tyler’s first question is worth thinking about (what exactly counts as a border region?), and the way I choose to define it more or less defines the direction in which this post is going to go. A border region, for the purposes of this post, is where a confluence of two or more cultures is observed. That is a ridiculously loose definition, I know, but this is a blogpost, so please let’s go with this for the moment.
  2. Does that definition necessarily mean better food? Well, that requires a definition of the phrase “better food”, but more variety and a greater degree of syncretism can reasonably be expected.
    • Think Massaman curry in Phuket, for example. Read this paragraph from that Wikipedia article to get a sense of what I’m trying to get at. This spice, frequently used in both Chinese cuisine and coastal Indian cuisine(s) is another good example.
    • Will the food in Chennai be necessarily better than in the interior parts of Tamil Nadu? Not necessarily, but it will be more varied in terms of influences, and especially as a tourist, that’s a good thing. It’s a good thing in general too, if you ask me!
  3. A confluence of culture is likely to be positively correlated with greater commerce, and that is likely to imply higher rent for real estate. Higher prices will imply a greater incentive to be better at making and selling food, so the quality will likely be higher (so long as you know where to look and how to choose). You could make the same point for costs of labour.
  4. More trade is also likely to imply fresher ingredients, and therefore better food.

What else am I missing?


So my answer would actually be yes, but it very much depends on how you define “border cuisine”.

Just one Object

When I teach courses in introductory statistics, my focus isn’t so much on helping students memorize definitions and formulas as it is on helping them understand the point of the core statistical concepts.

I often ask a student in class to tell us about their favorite movie, for example. Let’s assume that the student in question says “Dulhe Raja”.* Ok, I might say, rate the movie for us. And let’s assume that the student says 9.

I then ask the student if every single aspect of the movie is 9/10. All the songs, all of the fight sequences, all of the dialogues, every single directorial decision – is everything a 9/10? And the usual answer, of course, is no. Parts of the movie do much worse, and there might be some that are a perfect 10. But all in all, if the entire movie had to be summarized in just one number, that number would be nine (in that student’s opinion). Which, of course, is one way to think about averages. It’s a great way to summarize, distill or boil down a dataset into just one data point.

Of course, you would want to worry about whether each dimension of the movie has been given equal importance or otherwise. Dilli-6, for example, gets a score of 6/10 from me, but that’s because the music is just so utterly fantastic. But I’m giving much more importance to the music, and not that much importance to anything else (which, for me, was almost uniformly meh). And then, of course, we start to talk about weighted averages. And this also is a great way to segue into what standard deviation is all about. Then come the formulas and the problem solving, but that’s a whole other story.


So why am I speaking about this right now? Because I read an article in The Print the other day, which asked an interesting question that reminded me of all of what I’ve written about above:

If there was a cultural artefact that truly represents everything that is India today, what would it be?

https://theprint.in/opinion/pov/rasgulla-taj-mahal-sanskrit-what-if-i-told-you-to-pick-one-object-that-represents-india/1175979/

What a question to think about, no? Read the rest of the article to find out the author’s own answer, but in what follows, I want to try and think through my own answer to this question.

First, the recognition that we’re talking about a truly multi-dimensional problem. India is diverse in terms of her geography, her languages, her dance forms, her religions, her architecture, her food, her music – I can go on and on. As, I’m sure, can you!

So should we try and come up with an artefact that covers all (or as many dimensions as possible) at once? Maybe a movie, maybe a song, maybe an epic? But can (and should) a movie or a song encompass all of what India is across space and time?

The Mahabharata, maybe? A saga told in multiple languages, in various forms, from the viewpoint of many different protagonists, interpreted in a variety of ways over the centuries, and contains innumerable references to music, dance, food, sport, architecture besides so much else.

The only other artefact that might qualify must have something to do with food. We might have different ingredients, different techniques and different methods of preparing our food, but we all love a good meal, no? So might there be a dish, or a drink, that truly represents everything that India is today?

Tea? Nimbu paani? Khichdi?

Or does this dataset have so much variance that the average isn’t really a good representation?

I haven’t yet found an answer that satisfies me – which is a good thing! – but I do think I have found a good question to teach statistics better. No?

*This is a fantastic movie, and I will not be taking any questions.

Choosing Where to Eat

I just got back from a lovely holiday in Goa. Oodles of good food, loads of fantastic beer, hours of staring out at the sea, and not a laptop in sight for miles and miles. Just wonderful.

But if you know me at all, you’ll know that the first of these was the most important bit. Duh.


I spend a large chunk of my day thinking about food – what to make next, what to eat next, where to eat next. And today’s blogpost is about the last of these – where to eat next. How should one go about choosing where to eat?

  1. The book to begin with if you want to use economist-y principles is Tyler Cowen’s excellent “An Economist Gets Lunch”. The book is full of delightfully Cowenian advice:
    • Choose a restaurant where the patrons aren’t smiling (because that means the regulars are here to eat, not socialize)
    • When it comes to cuisines not native to the town you are in, choose a restaurant located on the outskirts of town rather than in the centre, it is more likely to have genuinely good food (lower rents, closer to recent immigrants into said town, both of which are likely to be good indicators of genuinely good food.)
    • The weirder a dish sounds relative to the rest of the menu, the more likely it is to be worth ordering (for why else would the restaurant choose to include it in the menu in the first place)
  2. Krish Ashok had a nice post on Instagram recently, where he pointed out that you should ignore negative reviews of restaurants, since the internet incentivizes one to be nasty and negative with one’s opinions.
  3. Here are my own tips, noting that your mileage may vary when it comes to adopting them:
    • Triangulate – if a restaurant has good reviews on Zomato, and on Google Maps and on blogs, it is likely to be good. A high rating only on Zomato is, to me, a worrying sign.
    • I tend to rate reviews on Google Maps higher because Google Maps seems to go out of its way to make putting up reviews more difficult (a somewhat unintuitive interface) and unrewarding (the gamification for reviewers simply isn’t good enough). So if somebody has taken the time and trouble to write a review, and that too a positive one, it is likely to be a very good restaurant.
    • YouTube reviews merit their own separate bullet point. There’s tons of stuff out there, but rely on folks who have put out a lot of stuff regularly, and tend to have a balance of 60:30:10. That is, 60% positive reviews, 30% so-so reviews and 10% negative ones. Note that this is a thumb rule! Once you find a channel you like, optimize for the very top of the 60%.
    • A limited menu and only one cuisine is a huge plus. This implies that the restaurant is focusing on what it knows best, and is not pandering to everybody. I’m even more reassured if the waiter informs me that certain items are not available, and my confidence in the quality goes up even more if they do so brusquely. I take it as a sign that they are focused on quality, and that they couldn’t care less if you leave. This must mean that there are enough “regulars”, and that can only be a good thing, right? I am from Pune, please note, so this may just be my genes having gotten used to rude service.
    • Make friends with the chef, the senior most waitstaff member, or both. I am a hopeless introvert in most social settings, but people who talk about food with passion are my people, and I have no problem striking up a conversation. Ask them to teach you how to appreciate the food they’re serving – what should you be looking out for on your palate, what details should you not be missing, and what variants of this dish are possible. Folks love to teach self-declared amateurs, and this will go a very, very long way in a restaurant.
    • I wish this weren’t true, but there is a very low bar for striking up a conversation in a restaurant in India. Politeness and a friendly demeanor are seriously underrated, use this fact to your advantage.
    • A corollary to the last point: try and visit a restaurant as early as possible. Most folks in urban India prefer to have late dinners – if you sit for dinner at 7 pm, you are likely to have fresher food and a not quite so busy staff who will be that much more willing to chat with you.
    • Avoid buffets like the plague. Unless you know the chef or the senior most staff member (or both). They will then not only recommend the best things to try, but will also give you freshly made dishes that they would like you to try. If you find such a restaurant, you’ve struck gold.
    • Avoid glitzy restaurants that are prominently located. They are more likely about signaling then about eating.
    • Well established and cheap watering holes are likely to have very good food. My favorite example in this regard is Pecos, in Bangalore, but there are lots of examples in all cities in India.

Mark Schatzker on Nutritional Wisdom

An Idli Thread on Twitter

And by the way, there really is a World Idli day. Wonders will never cease. I propose a Twitter based (natch) debate on whether World Sambar day should come before World Chutney day.

Food, by Krish Ashok

If you’re coming cross this thread for the first time, I envy you. Scroll up to the top, and drool your way through 🙂

Please read his book, Masala Lab, if you haven’t read it yet.

Team “Kam Nahi Padna Chahiye”

Every time we host a party at our home, we engage in a brief and spirited… let’s go with the word “discussion”.

Said discussion is not about what is going to be on the menu – we usually find ourselves in agreement about this aspect. It is, instead, about the quantity.

In every household around the world, I suppose, this discussion plays out every time there’s a party. One side of the debate will worry about how to fit in the leftovers in the refrigerator the next day, while the other will fret about – the horror! – there not being enough food on the table midway through a meal.

There is, I should mention, no “right” answer over here. Each side makes valid arguments, and each side has logic going for it. Now, me, personally, I quite like the idea of leftovers, because what can possibly be better than waking up at 3 in the morning for no good reason, waddling over to the fridge, and getting a big fat meaty slice of whatever one may find in there? But having been a part of running a household for a decade and change, I know the challenges that leftovers can pose in terms of storage.

You might by now be wondering about where I am going with this, but asking yourself which side of the debate you fall upon when it comes to this specific issue is also a good way to understand why formulating the null hypothesis can be so very challenging.


Let’s assume that there’s going to be four adults and two kids at a party.

How many chapatis should be made?

Should the null hypothesis be: We will eat exactly 16 chapatis tonight

With the alternate then being: 16 chapatis will either be too much or too little


Or should the null hypothesis be: We will eat 20 chapatis or more

With the alternate being: We will definitely eat less than 20 chapatis tonight.


The reason we end up having a “discussion” is because we can’t agree on which outcome we would rather avoid: that of potentially being embarrassed as hosts, or the one of standing, arms exasperatedly akimbo, in front of the refrigerator post-party.

It is the outcome we would rather avoid that guides us in our formation of the null hypothesis, in other words. We give it every chance to be true, and if we reject it, it is because we are almost entirely confident that we are right in rejecting it.

What is “almost entirely“?

That is the point of the “significant at 1%” or “5%” or “10%” sentence in academic papers.


Which, of course, is another way to think about it. This set of the null and the alternate…

H0: We will eat 20 chapatis or more

Ha: We will eat less than 20 chapatis

… I am not ok rejecting the null at even 1%. Or in the language of statistics, I am not ok with committing a Type I error, even at a probability (p-value) of 1%.

A Type I error is rejecting the null when it is true. So even a 1% chance that we and our guests would have wanted to eat more than 20 chapatis* to me means that we should get more than 20 chapatis made.

At this point in our discussions (we’re both economists, so these discussions really do take place at our home), my wife exasperatedly points out that not once has the food actually fallen short.

Ah, I say, triumphantly. Can you guarantee that it won’t this time around? 100% guarantee?

No? So you’re saying there’s a teeny-tiny 1% chance that we’ll have too few chapatis?

Well, then.

Boss.

Kam nahi padna chahiye!

*Don’t judge us, ok. Sometimes the curry just is that good.

Twitter Stories

Back in the day, when I had structure, regularity and a schedule here on EFE, Saturday used to be about five tweets that I enjoyed reading that week.

Which, on reflection (and some gentle prodding from Navin Kabra) wasn’t the brightest idea, because that’s what likes and RT’s are for on Twitter. So how about maybe a brief write-up based on a tweet that I read recently?

This week’s tweet that turns into a post is based on a variety of things. First, Nassim Nicholas Taleb.

The Black Swan is kind of like Thinking Fast and Slow, in the sense that everybody claims to have read it, and very few people actually have. If you haven’t read all of his books, please get started. The order doesn’t really matter, but if you’re asking, my favorite is Anti-Fragile.

There’s a lot to like about his books, his tweets and his outlook towards life, and this tweet is one example (note that I am talking about the pics in the reply, not the original tweet):

Now, the original tweet, reposted as a stand-alone:

So what is the company about?

Nasser Jaber is cofounder of the Migrant Kitchen, a catering company and social impact organization that hires immigrants, migrants, and undocumented workers to both train them in commercial cooking as well as help gain their cuisines more exposure in the marketplace.

https://stories.zagat.com/posts/nasser-jaber-on-creating-jobs-through-immigrant-cuisine

Read the whole article! I got to learn about quipe (kibbeh, apparently), and esfiha (the spelling differs based on context, so my apologies if I got it “wrong”), among other things.

Twitter is a wonderful, wonderful way to learn more about the world, but it is like a garden, in the sense that constant weeding is required. But when you tend to it just so, it is completely worth the effort!

If you have had moments of serendipity on Twitter that you’d like to share, please, send them along. @ashish2727 on Twitter.

Thanks, and enjoy the weekend 🙂

Etc: Links for 20th December, 2019

  1. The coolest things that David Perell learnt in 2019. He has a paragraph on Twitter, from Bill Gurley, that I wholeheartedly agree with. Tempers run high on Twitter, true, but it is a magnificent learning tool for me.
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    “One of the examples is a famous New York City physician who was renowned for his ability to predict that patients would get typhoid. He predicted the sickness time and again. He would palpate their tounge (feel around their tongue) and predict, weeks before patients had a single symptom, over and over, and became famous, and as one of his colleagues said, he was a more productive carrier of typhoid than even Typhoid Mary because he was giving his patients Typhoid with his hands. In that case, the feedback he was receiving was reinforcing exactly the wrong lesson.”
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  2. Two articles that I got to read as a consequence of subscribing to Joanna Lobo’s Newsletter (if you are interested in writing, either as a hobby or a career, this is a newsletter worth subscribing to). The first is about the perils of comfort food…
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    “Every meal was meticulously pre-portioned and packaged for every individual. We never ate family-style, which was how I grew up eating, and how I learned that portion control is often not within your control: You are not just eating for yourself, and the choice to eat (and how much) often symbolizes love and affection more than physical nourishment. What is considered a “serving” when your chopsticks keep dipping back into shared plates and the diet app you use doesn’t even know what 鱼香茄子 (Chinese eggplant with garlic sauce) is? How can you not overeat when people were heaping dishes onto your plate without you asking? Is it rude to not finish that tofu someone offered you? What is fullness?”
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  3. “A Zomato spokesperson tells Open they are currently in the process of doing away with their food-reviewing levels. The titles have already been removed from the mobile app, the spokesperson says, and they will soon be removed from the website too. According to her, this has nothing to do with complaints about soliciting money, or restaurants and connoisseurs coming together to bump up an establishment’s ratings. “We are just coming up with a newer version, a new engagement tool for users,” the spokesperson says over the phone.”
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    A long read about gaming restaurant reviews.
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  4. Bourbaki’s influence is still alive and well. Now in “his” 80th year of research, in 2016 “he” published the 11th volume of the “Elements of Mathematics”. The Bourbaki group, with its ever-changing cast of members, still holds regular seminars at the University of Paris.
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    A lovely essay from the Madras Courier about Bourbaki, the “guy”.
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  5. Lots of links to work through in this video, but worth your time! Stats nerds only.