Yes, height. There are some new findings on the role (or lack thereof) of genetics in how tall we grow, from either sides of the West Bengal-Bangladesh border

There’s some interesting new evidence to inform the debate over one of the most divisive issues in development in India at the moment - the role that genetics have in explaining Indians’ heights.

Indians are among the shortest people in the world, and within India, people in richer states are taller than those in poorer states.

It is well established that children who do not get adequate nutrition between the ages of 0-2 are shorter than they could have been (i.e. their genetic potential). There is also now strong evidence to show that lack of access to proper sanitation and the poor social and health status of women affects the nutritional status of children, thus leading to low heights.

What there isn’t complete consensus about though is to what extent genetic differences explain inter-country and intra-country variations in heights. Most economists who work in this field have told me that there is very little evidence of such genetic variation and what difference there is explains very little of the difference in heights. One of the key dissenting voices has been that of Columbia economist Arvind Panagariya, whose piece in the Economic and Political Weekly saying that genetics explained a large part of Indian children’s low heights was rebutted by six others.

As with most such macro debates, a collection of micro studies some times goes much further in making the picture clear. Enter, a fascinating new study by Arabinda Ghosh, Ashish Gupta and Dean Spears that compares the heights of children in West Bengal with those in what was East Bengal, i.e. Bangladesh. There cannot conceivably much genetic difference between these two neighbouring populations that became part of separate nation states relatively recently.

Mr. Ghosh et al find that on average children in West Bengal are taller, but are also richer (average incomes are higher in West Bengal than Bangladesh). But when you compare children of similar wealth across the border, kids in Bangladesh are significantly taller. A combination of the better social status of women in Bangladesh and better sanitation (less open defecation) statistically accounts for almost all of this difference, the researchers find.

So here’s a provocative thought: are people who the historical accident of Partition placed on the Indian side of the border better off because they’re richer and slightly taller? Or are those who ended up in Bangladesh better off because even though poorer on average, their health indicators are better than those equally poor across the border?

Based on this study alone, Mr. Ghosh et al cannot conclusively answer this. “I think part of the message is that there are many dimensions of well-being: economic wealth matters, disease matters, social status matters,” Mr. Spears explained to me. Getting richer can make you taller, and better sanitation can do that too; which path a country takes is, I suppose, what politics is.