Are immigrants on welfare because they are more likely to be eligible or because they are more likely to claim benefits for which they are eligible? The answer is politically important, but because most current research on immigration and welfare is based on data from the U.S., the answer is...

The use of drugs in high-performance sports (doping) is a common pool resource (CPR) dilemma: regardless of the number of other athletes who dope, the athlete with strong tastes for victory will find doping optimal; yet if all athletes dope, they all bear negative health consequences, although...