Can Yelp Help Track Food-Borne Illness?

I have been working on a paper about food-borne illness lately, and one of the things I have learned is that for a specific outbreak of food-borne illness to show up in the Centers for Disease Control’s (CDC) data, the stars need to be properly aligned.

Specifically, you have to get sick enough that you see the doctor about it. Then, upon determining that your illness was food-borne, your doctor needs to notify the health authorities of the county you live in. Finally, the health authorities in your county need to notify the CDC. So necessarily, the CDC data on food-borne illnesses is an undercount, and just how systematic is this undercounting varies by state… which poses a number of econometric problems for this researcher. Continue reading

Who Was the First to Use Randomization in Development Economics, and When?

If you answered “Probably Esther Duflo, sometime in the early 2000s?” just as I did, you were wrong, just as I was.

As it turns, Immink and Viteri were the first to use randomization in a two-part article (part 1 is here; part 2 is there) testing the efficiency wage hypothesis published in the Journal of Development Economics in 1981: Continue reading

Income and Population Growth

Do changes in income cause changes in the population? In other words, can wealthier countries sustain more people? A new article by Markus Brückner and Hannes Schwandt in the Economic Journal answers in the affirmative, finding that this is because of increased fertility and lowered child mortality:

Do populations grow as countries become richer? In this paper we estimate the effects on population growth of shocks to national income that are plausibly exogenous and unlikely to be driven by technological change. For a panel of over 139 countries spanning the period 1960-2007 we interact changes in international oil prices with countries’ average net-export shares of oil in GDP. Controlling for country and time fixed effects, we find that this measure of oil price induced income growth is positively associated with population growth. The IV estimates indicate that a one percentage point increase in GDP per capita growth over a ten year period increases countries’ population growth by around 0.1 percentage points. Further, we find that this population effect results from both a positive effect on fertility and a negative effect on infant and child mortality.

Critical Thinking ≠ Being a Contrarian


Our best college students are very good at being critical. In fact being smart, for many, means being critical. Having strong critical skills shows that you will not be easily fooled. It is a sign of sophistication …

The combination of resistance to influence and deflection of responsibility by confessing to one’s advantages is a sure sign of one’s ability to negotiate the politics of learning on campus. But this ability will not take you very far beyond the university. Taking things apart, or taking people down, can provide the satisfactions of cynicism. But this is thin gruel.

The skill at unmasking error, or simple intellectual one-upmanship, is not totally without value, but we should be wary of creating a class of self-satisfied debunkers … In overdeveloping the capacity to show how texts, institutions or people fail to accomplish what they set out to do, we may be depriving students of the chance to learn as much as possible from what they study.

From an excellent post on the New York Times‘ The Stone blog by Michael S. Roth, president of Wesleyan University, titled “Young Minds in Critical Condition.” After almost 15 years teaching in North American universities, I can only agree. Continue reading