What is development economics?

That was a question sent in by a student recently, and today’s essay is an attempt to answer the question.

Have you heard of the tsetse fly? Unless you are a student of biology, or from Africa, it is unlikely that you have. And there’s no reason for you to have heard of it, of course. On the other hand, if you were to be from Africa, and from a long time ago, you likely would not only have heard of the tsetse fly, but you would have dreaded it.

Why would you have dreaded it? Because the tsetse fly feeds on the blood of vertebrate animals, and in doing so, also manages to transmit diseases between species. And this fly was so very efficient at transmitting diseases that it actually prevented the emergence of animal husbandry in those parts of Africa where it was both present and dominant.

Worse: research has established that the existence of the tsetse fly in certain parts of Africa has at least partially contributed to those parts of Africa remaining relatively underdeveloped today.

Ethnic groups inhabiting TseTse-suitable areas were less likely to use domesticated animals and the plow, less likely to be politically centralized, and had a lower population density. These correlations are not found in the tropics outside of Africa, where the fly does not exist. The evidence suggests current economic performance is affected by the TseTse through the channel of precolonial political centralization.


That’s what development economists do: they try and figure out which parts of the world are not doing well. Then they try and figure out why (imagine being able to identify a fly as a potential cause of underdevelopment!). And finally, they try to recommend policies that might make the situation better.

Three Big Questions

When I teach courses in development economics, I often introduce the subject by speaking about three “big picture” questions:

  1. What does the world look like?
  2. Why does it look the way it does?
  3. What can we do to make it better?

And honestly, that is really all you need to think about when you want to understand what development economists do. Let’s tackle each of these questions in turn.

What does the world look like?

Good development economists don’t begin with recommendations and policy measures. That’s a long way down the road. They begin by trying to paint for themselves a picture of the world.

My favorite way to paint for myself a picture of the world is by using a freely available online tool called Gapminder.

Click here to open Gapminder in your browser

What are we looking at? Hans Rosling, the Genius (I don’t use the word lightly, and the capitalized G is intentional) who came up with this tool, used to call this chart the “Health and Wealth” chart.

Inflation adjusted, purchasing power parity adjusted per capita income for each country is plotted against the life expectancy for the citizens of that country. The color coding shows you which part of the world that country is from, and the size of the bubble indicates the population in that country.

Well, ok – but what does it tell us?

Well, here’s what it tells me – see if you agree with my understanding. It tells me that the reason economists harp on so about increasing income (GDP) for all nations is not because getting rich is an end in and of itself. It is the means to an end – that end in this case being better health.

Two caveats: higher life expectancy doesn’t necessarily mean better health. But in this case, I think it is an acceptable proxy. Second, correlation is not necessarily causation! Higher wealth may not necessarily be causing better health. Maybe better health is causing higher wealth? Maybe some other variable is causing both of these things? Maybe it is all of these and more?

But all those caveats aside, at first glance, a basic fact emerges:

There is no country that is at the top left of this chart, and there is no country at the bottom right of this chart.

Poor countries tend to not do well in terms of life expectancy, and rich countries tend to do well in terms of life expectancy. If I want the members of my family to live longer, I would want my country to be towards the top right of this chart.

But back to the central question: what does the world look like? This is a generalization, of course, but most of the African nations tend to lie towards the bottom left. Most of the European nations tend to lie towards the top right. And Asian nations (and some South American nations) tend to lie somewhere in the middle.

That’s one answer to the question we were trying to answer in this section: what does the world look like?

But there are other answer possible! Here are just two to get you started:

  1. Read the excellent introductory chapter in Partha Dasgupta’s “A Very Short Introduction to Economics”
  2. Play around with the World Bank Atlas, a most excellent data repository.

Why does the world look the way it does?

The Magic That Happens When You Hit Play in Gapminder

I have been using Gapminder for over 12 years now, but I am yet to get tired of watching that video. In fact, as I often tell my students, you could do a lot worse than spending time with Gapminder open in one tab, and Wikipedia in the other.

(On a tangential note, take a look at what happened to the world between 1918 and 1921. That’s the Spanish flu at work.)

Why did I include this video in this blogpost?

Because it helps us begin to think about the answer to the second question: why does the world look the way it does?

The world looks the way it does today because some countries were able to steal a march on others about two hundred years ago. The United Kingdom, the United States of America, Japan, Germany and some other nations started moving towards the right top of the chart before other countries could. You could, in fact, make an argument these countries were able to move to the right top by making sure that the other countries stayed at the bottom left!

And when you make that argument, you begin to try and answer the second question – this argument is the anti-imperialist stance. The Asian and African colonies of the European powers of the 19th century lag behind as much as they do today because they were colonies: that’s one candidate for explaining why the world looks the way it does.

The tse-tse fly (remember?) is another candidate for a more localized answer to the second question. Politics, race, religion, geography, caste, gender, openness to innovation – there are so, so many candidate answers! People can (and do!) spend entire careers making their way through just one of these candidates.

By the way, if you would like to read books about this topic – why does the world look like the way it does – here are two absolute must-reads:

  1. Guns, Germs and Steel, by Jared Diamond
  2. Why Nations Fail, by Acemoglu and Robinson

What can we do to make it better?

Can chickens cure poverty in Africa?

I’m not joking! That was a genuine proposal, made by this guy who you may have heard of. Started a software firm, dabbled in philanthropy, and is now engaged in trying to literally save the world. Yes: Bill Gates. His master plan to save Africa involved giving everybody a chicken.

Our foundation is betting on chickens. Alongside partners throughout sub-Saharan Africa, we are working to create sustainable market systems for poultry. It’s especially important for these systems to make sure farmers can buy birds that have been properly vaccinated and are well suited to the local growing conditions. Our goal: to eventually help 30 percent of the rural families in sub-Saharan Africa raise improved breeds of vaccinated chickens, up from just 5 percent now.


Well, I exaggerate, of course. Not literally giving everybody in Africa a chicken – but something along those lines.

Development economists were less than impressed:

But first, let’s talk about poultry. I think we can agree that we can only give away so many chickens. You’ve said that a family that receives five hens could eventually earn $1,000 annually, assuming a per-bird price of $5. But would that still be true when a third of your neighbors are in the same business? As supply goes up, I’d expect the price and profits to come down. And moving to an economy in which 30 percent of rural Africans sell chickens is a humongous increase in supply.


And to make matters worse, other development economists were less than impressed with the development economists who were less than impressed with Bill Gates’ chickens:

I have friends/alumni/colleagues working around the world in many facets of the challenge of development. I have friends working for the Prime Minister of India. I have friends working for the President of Indonesia. I have friends working on the conflict in Yemen. I have friends working as civil society activists in Egypt. I have had policy discussions with policy makers all over the world. I worked for 15 years in the World Bank. I have taught development at Harvard for 15 years. In all of those conversations with friends, colleagues, policy makers, and students all kinds of difficult and pressing development questions have arisen that research could address. Never, ever, ever has “chickens versus cash” arisen as an issue at all, much less as the remotely possible “best investment” in research.


By the way, that blog post that I quoted above? It has possibly my all time favorite title ever: Getting Kinky with Chickens.

Why am I telling you all this? Because allow me to let you in on a dirty little secret: there is zero consensus on what is the correct answer to the third question.

Well, OK, zero consensus is an exaggeration. But it ain’t a settled issue, no sir.

That is, nobody has come up with a definitive, one-size-fits-all answer to the question, “What can we do to make the world better?”

Let’s parse through the question. That might help us understand why it is such a controversial one.

What can we do to make the world better?

  1. Who, exactly, is “we”? That is, who is in charge of decision making when it comes to making things better? Do democracies work better? Or do autocracies? Or something in between?
    Remember, we are not asking which political system is the best from a moral, or political, perspective. We are asking which system is likely to give us the most rapid growth. Was Singapore under Lee Kuan Yew a true, participatory democracy, or was it a democracy with Asian characteristics? What about South Korea under General Park? And while we’re on the subject, an autocracy is not by itself a guarantee of rapid growth! Pakistan, Cambodia are two examples from our own neighborhood.
    Also remember: just because a system may give us more rapid economic growth doesn’t mean it is the best system to use. China is the obvious country to think about in this regard!
  2. Do we really need to “do” stuff, or is it more about just getting out of the way, and letting the economy work it’s magic?

3. Are we agreed on what “better” means? Lesser pollution comes at the cost of lesser industrialization, for example. Are we so sure that all seven billion of us can identify the exact point on the spectrum that works best? And if not, then we’re back to the first point: who is “we”?

And hey, even if you could imagine a world in which we somehow, magically get everybody to agree on “What can we do to make the world a better place?”, we’d begin a new round of battles, centered around a new question.

“How?” – and on this point, last year’s Nobel Prize winners have won accolades and received brickbats in equal measure.

Still, there is some good news. The unsettled nature of the debate means that this is extremely fertile ground to work upon, and you can count on development economics as a field remaining a fundamentally interesting one to work in for years, if not decades, to come.

And that, my friend(s), is what development economics is all about!

EC101: Links for 5th December, 2019




    The mastering assignment is what they assume when they focus on
    down from the elite. ”
    Dierdre McCloskey (as usual) doesn’t pull punches.
  5. A set of links about the topic from Oxfam.

RoW: Links for 14th August, 2019

Five links about gun control from the United States of America:

  1. First, from Chriss Blattman, who knows a thing or two about violence.
  2. Slatestarcodex, on trying to make sense of the data
  3. and what the comments section from that blog has to say.
  4. Gun control, the Japanese way.
  5. To circle back to the beginning, a contemplative article from Vox.