Chad Clark's Open Journal : 2007-10-04

1) Menstrual cycle linked to female stripper's income.

The Psychology Today article reads:

  Psychologist Geoffrey Miller and colleagues tapped the talent at local
  gentlemen's clubs and counted tips made on lap dances. Dancers made about
  $70 an hour during their peak period of fertility, versus about $35 while
  menstruating and $50 in between.
  
  ...
  
  Women on the pill averaged $37 (and had no performance peak) versus $53
  for women off-pill. The contraceptive produces hormonal cues indicating
  early pregnancy, not an enticing target for a would-be suitor. Birth
  control could lead to many thousands of dollars lost every year.