The GenealogyInTime Magazine Newsletter for 14 July 2012 includes an interesting item Marriage and Age Differences. It points out a genealogy brick wall solution showing how to estimate the birth date of one spouse knowing the birth date of the other spouse and the year in which they were married.
The source is an item Marriage and life expectancy from the Max Planck Institute for Demographic Research which also has marriage advice.
A woman's life expectancy is shorter the greater the age difference from her husband, irrespective of whether she is younger or older than him. However, the younger his wife, the longer a man lives. Women marrying a partner seven to nine years younger increase their mortality risk by 20 percent compared to couples where both partners are the same age. But the mortality risk of a husband who is seven to nine years older than his wife is reduced by eleven percent.Other interesting items at the Institute site include: What the electric meter tells us about the birthrate; and You are where you e-mail.