LIVE in a crowded South Asian city and a host of problems—smog, contagious disease, corruption—may plague you. Each winter, the air grows foul. The monsoon season brings mosquitoes, bloodsuckers capable of carrying nasties such as dengue and malaria. As cities expand and people are packed closer, they are more likely to pass on infections. Overwhelmed municipalities, especially if weakened by corruption, offer a weak response... more