Ethnic heterogeneity and natural disasters

Some countries seems to be very poorly located, as they are in the path of all sorts of natural disasters. But some do better than others in coping with their perilous situation. In particular, death tolls from cataclysms seems to be, in general, of an order of magnitude larger in developing countries. What else could influence such numbers?

Eiji Yamamura, from a rich and homogeneous country that does quite well with earthquakes, tsunamis and typhoons, studies ethnic heterogeneity in two different ways in this regard. The first is ethnic polarization, which describes how close the distribution of ethnic group is from a fifty-fifty one, and ethnic fractionalization, which can be interpreted as the probability that two random people are from the same ethnic group. Once one adds the miracle instrument of cross-country regressions, legal origins, the first indicator has shows that heterogeneity has a positive impact on natural disaster deaths (meaning more of them), while the second has none.

Now Yamamamura takes this as a sign that ethnic polarization is a better indicator of ethnic heterogeneity than ethnic fractionalization. This looks like some seriously flawed reasoning here, which is repeated several times in the papers: the fact that some indicator tests favorably some hypothesis does not necessarily mean that it measures what the hypothesis says. What if in really the hypothesis is false? And in any case, on what theory would this hypothesis be based? I can easily imagine good reasons why homogeneity would lead to fewer deaths, a better social cohesion that leads to better institutions coping with disasters, like in Japan.

Econophysics: an introduction

I have criticized a number of times Econophysics as a rather naive venture of physicists into Economics, where there is too much focus on "automatic" data exploration and too little use of theory and understanding of what the data measure. But may it is just my prejudice against and my ignorance of Econophysics.

B. G. Sharma, Sadhana Agrawal, Malti Sharma, D. P. Bisen and Ravi Sharma offer in six pages an account of what Econophysics is, what its goals are, what it can contribute and where it is headed. The basic idea is that economic agents are like particles in that they are in large numbers and interact in complex ways. The dynamics of such complex processes are studied with powerful statistical tools in Physics, and physicists think that this should also apply to Economics. The focus is very much on the stock market, probably because physicists have realized where money can be made. There is no sense that there would be an attempt to improve welfare. They are also much more likely to completely discard a model in one set of observations does not corroborate it. Physicists are especially critical of how economists stick to rejected dogmas and of their inability to explain how small shocks can pan out into large crises.

The focus is really on the description of data process and documenting there statistical properties. In particular, econophysicists want to find ways to exploit even the smallest opportunities for arbitrage by finding, often through obscure and complex black box processes, the right price of an asset at any moment in time. However, there is no attempt at understanding why these arbitrage opportunities arise, say because of some form of irrationality, asymmetric information or perverse interactions in the price mechanism. From this I conclude that Econophysics can be interesting to make money on the stock market, but at least at this point, does not help us in any way in understanding why the world is like it is. Which I find rather ironic for Physics.

The Internet did not raise a generation of loners

The image of the basement-dwelling World-of-Warcraft-playing loner is often shown as an example of the adverse impact of the Internet on social capital and in particular social interactions. Whether this is true is not so obvious, as the Internet also makes possible social interactions that could not exist before, as this blog shows in a limited way.

Stefan Bauernschuster, Oliver Falck and Ludger Woessmann study the impact of broadband Internet on social capital using a natural experiment in Eastern Germany. There, some choice by the telecommunications provider resulted in 11% of East German households to be on OPAL lines instead of DSL, which better supports high speeds. Using the German Socio-Economic Panel, they measure social capital with the frequency of going out, visiting friends and performing volunteer work. They find that Internet access has no visible impact on social capital. To the contrary, for children it seems to enhance social capital, possibly because it makes them aware of new opportunities to interact in real life. This is in stark contrast with television use, which has many times been shown to be detrimental to social capital, likely because it is a one-way communication, while the Internet can build two-way communication.

Animals as forecasters

Futures markets and in particular prediction markets are a good way to hedge against various risks as well as establish what people really think about the likelihood of some event. As they a putting money on the line, these markets are deemed (and have proven) to be more really than surveys and polls. Of particular interest in this context was the short-lived "terrorism futures market" organized by the Pentagon, which was supposed to offer an additional tool for predicting terrorist threats, and which would allow those who could suffer from terrorism to buy insurance against it. Unfortunately, there was also a fear that threats could materialize because of the market, as people would try to manipulate it.

Adi Schnytzer and Yisrael Schnytzer point out that there is another potential for prediction markets: natural disasters. Of course, we humans are so far not particularly good at forecasting such events as earthquakes, but some animals have evolved a sixth sense in this respect that is rather underexploited. While it seems difficult for scientists to drum up money to study this, maybe because this technology does not seem credible or usable, the Schnytzers point out that if prediction markets are created for natural disasters, then funding would emerge if money is to be made. And this would also establish whether these theories have credibility.

The economic behavior of bees

I find it fascinating that there is also plenty of Economics in the animal kingdom. Two recent papers about bees just caught my attention.

Antoine Champetier studies the interaction of bees and farmers, as bees play an important role in pollination and are thought to be subject to a mysterious decline in numbers. He takes California almonds as an example and builds a model of pollination supply with hive owners and bees that forage. One aspect appears to be rather important: economies of scale in the hive, as larger hives have an easier time regulating the temperature and can devote more time to more aggressive foraging. Champetier formulates a spatial model of foraging and coordination in the bee colony, where energy used and gained by foraging is assessed, as well as time costs in each step of pollen acquisition and storage.

Noam Bar-Shai, Tamar Keasar and Avi Shmida study what makes that a bee departs early or stays longer in a flower patch. Looking at videos, they concluded that bees cannot count, but are rather governed by clues left by odor marks (to prevent revisiting the same flowers) and current foraging success.

Breastfeeding and cognitive skills

Breastfeeding is now almost universally promoted as the healthiest way to feed a baby. And indeed, while breastfed babies are a little smaller and than bottle-fed ones and gain a little less weight, they are healthier, it is thought mainly because the mother milk transmits antibodies and relevant nutrients. But not every mother breast feeds, maybe because not every mother realizes all the benefits, or because some of the costs are high (time management for working mothers or aesthetic issues). Or there are some other benefits that are not well known.

Maria Iacovou and Almudena Sevilla-Sanz report that breastfeeding has significant positive impacts on cognitive skills (reading, writing and mathematics). While this correlation is well known, it may be spurious because mothers who breastfeed are more likely to be well educated (Irish example), and their children are also more likely to be well educated as well. The obvious way to overcome this statistical issue, a randomized trial, is not feasible on ethical grounds. What Iacovou and Sevilla-Sanz do is use propensity score matching, which essentially matches babies that have the same characteristics but breastfeeding and then compare their cognitive skills. What is particularly impressive in this study is that the retained characteristics are very broad beyond baby demographics and health, including parent characteristics such as education, job, income, and even pre-birth attitude towards breastfeeding or home and neighborhood. And even after controlling for all these variables, the impact of breastfeeding is still significant on babies from Bristol (England), and it may even grow with age.