Math

Not the usual fare, but I'm related to too many mathematicians (and lost too many high school math competitions to children of Russian immigrants) to pass this one up.


The Collapse of the Soviet Union and the Productivity of American Mathematicians
George J. Borjas, Kirk B. Doran

Abstract: It has been difficult to open up the black box of knowledge production. We use unique international data on the publications, citations, and affiliations of mathematicians to examine the impact of a large post-1992 influx of Soviet mathematicians on the productivity of their American counterparts. We find a negative productivity effect on those mathematicians whose research overlapped with that of the Soviets. We also document an increased mobility rate (to lower-quality institutions and out of active publishing) and a reduced likelihood of producing “home run” papers. Although the total product of the pre-existing American mathematicians shrank, the Soviet contribution to American mathematics filled in the gap. However, there is no evidence that the Soviets greatly increased the size of the “mathematics pie.” Finally, we find that there are significant international differences in the productivity effects of the collapse of the Soviet Union, and that these international differences can be explained by both differences in the size of the émigré flow into the various countries and in how connected each country is to the global market for mathematical publications.

More on slack labor markets affecting conflict

Kyle Meng points us to this recent NBER working paper. See this related post and this one too.

Building Peace: The Impact of Aid on the Labor Market for Insurgents
by Radha Iyengar, Jonathan Monten, Matthew Hanson

Abstract: Employment growth could reduce violence during civil conflicts.  To determine if increased employment affects violence we analyzed varying employment in development programs run by different US military divisions in Iraqi districts.  Employment levels vary with funding periods and the military division in charge.  Controlling for
variability between districts, we find that a 10% increase in labor-related spending generates a 15-20% decline in labor-intensive insurgent violence.  Overall the 10% spending increase is associated with a nearly 10% violence reduction, due to reduction in attacks which kill civilians, but increased attacks against the military. These findings indicate that labor-intensive development programs can reduce violence during insurgencies.

Weak labor markets make army-building cheaper

It's generally accepted that civil conflict is more likely when a county's economic growth slows down (see here).  One hypothesis to explain this phenomena is that when economies perform poorly, soldiering becomes a relatively more appealing job and attracts individuals who might otherwise work elsewhere.  The argument goes that this makes it cheaper for opposition groups to build forces to fight an established government, thereby making conflict more likely.

In what seems like support for this idea (albeit in a different context), I heard this story reporting that these labor market dynamics appear to be obvious in the United States and are accepted wisdom at the Pentagon:

"A recession really does make recruiting less challenging than it otherwise would be," says Dr. Curtis Gilroy, who oversees active duty military recruiting nationwide. "We're in our third year in which all active duty services have achieved their numerical recruiting goals and either met or exceeded their recruit quality benchmarks as well." 

So the military gains not just more recruits, but better ones. Test scores are up along with the number of recruits who graduated high school. Today the military is letting in fewer recruits with waivers for minor criminal histories or past drug use. 

For all services, the quality of recruits is the highest it's been in nearly two decades. This, even as the nation is at war — and the risks of military service are as clear as ever.

Fraction of recruits graduating from high school,
 a measure of "recruit quality" used by the military.