endocrine hypothesis. For example, there must be in the population many men who have regularly donated blood every six months for many years. Obviously this is not equivalent to a monthly menstrual bleed. Nevertheless it would be interesting to see whether these men are in any way protected against coronary thrombosis as compared with a group of non-donors. (2) If true the concept would mean th...

Editor: STANFORD WESSLER, M.D.

Theory and intuition tell us that the imposition of stringent environmental policies by a given country will reduce its net exports of commodities produced using pollution-intensive industries. It is therefore surprising that many empirical studies of international commodity trade have failed to …nd evidence of this e¤ect. This study o¤ers a new, highly focused test of the pollution haven hypot...