India, Bangladesh, GDP. Sigh.

When I explain GDP to folks unfamiliar with the concept, I often use the analogy of marks.

“Do you”, I intone in the most professorial voice I can muster, “remember how many marks you scored in your math exam when you were in the 4th grade?”

The point behind asking that question is to help the class realize that there were many other things going on in their life in the 4th grade. The measurement of how well you did on the specific questions you were asked in that test on that day do very little to show you how much math you actually learnt that year. Leave alone, of course, the question of how little the math test had to do with all of what you learnt while you were in the 4th grade.

A similar point was made about GDP recently, in the Business Standard:

Take GDP first. In India, we don’t measure the output of 65 per cent of the economy and make only well-informed guesses about the remaining 35 per cent.

That’s exactly right, of course. You shouldn’t obsess over GDP numbers, much like you shouldn’t obsess over grades. But we do obsess over both!

And the analogy between marks and GDP works really well especially now, because when it comes to GDP, we now have a Sharmaji ka beta in the neighbourhood.

Hello, Bangladesh.

About two years ago, India’s Home Minister Amit Shah spoke of “infiltrators” who were hollowing out the country “like termites”. A Minister from Bangladesh retorted that Shah’s statement was “inappropriate”, “unwanted”, and “not based on information”. The IMF’s recent per capita GDP projections for South Asian countries show that the alleged ‘termite factory’ is shining — Bangladesh, which has been doing better than both India and Pakistan on social and human development indicators for several years now, is also beginning to march ahead on the economic front.

In much the same way that you shouldn’t compare marks obtained by students, you really shouldn’t compare GDP per capita between nations.

But (and you knew there was a but coming along, didn’t you), as I also say in my classes – what else you got, eh? It’s all well and good to say we shouldn’t, but it’s not like we have readymade alternatives. And if you take the GDP factory away from us economists, how do we fill our days?

TCA Srinavasa-Raghavan, in the same column cited above, has three answers:

Only three things: Food inflation, because it has a direct bearing on welfare; foreign exchange reserves, because they serve as a powerful signalling device to foreign investors and sellers of goods; and the revenue deficit. These are the only things the Centre has total control over. In determining all other indicators, the states play a big role.

Read the whole article (which, I’m sorry, may well be behind a paywall). I don’t necessarily agree with all of it, about which more below, but the point that GDP is overrated as a useful barometer for the state of the economy is a point I agree with wholeheartedly.

TCA’s suggestions about what is to be used instead (food inflation, the revenue deficit and forex reserves) are worth considering, but there is a long list of alternatives that have been suggested. Here is just one example:

Provincial officials have long been suspected of overstating growth. Adding their figures together suggests that China’s economy was $364 billion bigger in 2009 than the total in the national accounts. Mr Li preferred to track Liaoning’s economy by looking at other indicators: the cargo volume on the province’s railways, electricity consumption and loans disbursed by banks.

Other folks may come up with other things to use as a proxy for measuring the state of the economy, but really, it is the old story of the six blind men and the elephant all over again. Whatever you use will give you only a limited picture. That’s just the nature of the beast.

Worse! Whatever you agree to measure instead of GDP immediately becomes susceptible to Goodhart’s Law:

In a paper published in 1997, Anthropologist Marilyn Strathern generalized Goodhart’s law beyond statistics and control to evaluation more broadly. The phrase commonly referred to as Goodhart’s law comes from Strathern’s paper, not from any of Goodhart’s writings:

When a measure becomes a target, it ceases to be a good measure.

(Emphasis added)

So sure, you could ask that food inflation, revenue deficits and forex reserves be the target. But it’ll just be cobras or rat tails all over again.

So GDP, whether you like it or not, whether its measurement is favorable or not, is not going to go away anytime soon, whether in India or elsewhere.

Consider the concluding paragraph from a column in the Livemint yesterday by R Jagannathan:

This does not make GDP calculations worthless, but the real focus should be on sectors. More than macroeconomics, sectoral understanding and microeconomics ought to be central to policy-making. Future GDP will best be estimated as a sum of its parts, and not as a whole extrapolated from numbers in the more visible parts of the economy.

Yes, well, sure. Absolutely.

Now if only we could figure out the how.