Deepak Lal, an economist at the University of California, has warned India against signing global treatises such as the Persistent Organic Pollutants (POPs) Treaty and the Biodiversity convention. While European, US and foreign aid agencies' scepticism is urging a ban on the use of DDT, Lal argues, "if India foolishly signs this convention it will seriously damage the nation's health. DDT is the most cost-effective controller of diseases spread by bugs like flies and mosquitoes that has ever been produced."