And Plod finds him searching under the lamp post. "Is this where you lost them?" "Nah, over there!" " So why are you looking here, under the lamp post?" "Because this is where there's the light to find them!"
No, I didn't think it was all that funny when I first heard it when I was five either. However, it is a useful description of what some people do. Look where it's easy to look rather than where they might find something. And is this true of economists? Is there, for example, much too much research done on the economies of rich countries and too little on those of poor ones?
Fact 1: “Just” Income: There is a strong correlation between GDP and publications—a doubling of GDP leads to a 37 percent increase in the number of publications on the country. The US is bang on the regression line relating GDP to publications—a lot more is produced on the US because it is big and rich. Surprisingly, most countries in Sub-Saharan Africa are also on the regression line! In fact, there is no “SSA penalty” in the production of empirical research—there is very little work on most SSA countries mostly because they are poor and small. That 36,649 papers were written on the US between 1985 and 2004 relative to 4 on Burundi, 5 on Benin or 20 on Niger is largely explained by income and population size.
You could read that as a yes: and you probably will read that as a yes if you're subject to the great folly of our times. That it is poverty that needs to be explained, poverty that is unusual, some even insist that poverty is created. Something which simply isn't so: poverty is the natural condition, poverty is how all of the world has lived until recent centuries and poverty is how far too much of the world still lives.
It is the creation of wealth which is the historically unusual thing: indeed, the existence of an economy complex enough to be worth studying which is the exception. So it makes perfect sense that economic research should concentrate on the rich countries. They're the place that have economies to study for a start. But much more important, it's riches, wealth, that are the keys we are searching for: that they happen to exist where there are the lamp posts of universities, libraries and a really good cup of coffee to imbibe while researching is convenient, sure, but then that's just another way of saying, the existence of universities, libraries, and good coffee, that these places have economies worth studying.
Plus, of course, the surplus over and above day to day survival for the population sufficient to support researchers to try and work out why there's a surplus capable of supporting researchers.