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!