Common Law Marriage and Teen Births

Whether common law marriage (CLM) in the US affects teen birth rates is the central question we address. CLM effects were identified through cross-state and time variation, as four states repealed the law over the period of study. Using microdata from Current Population Survey Fertility supplements 1990–2010 and state-level data from CDC Vital Statistics 1988–2012 we found that, in the states where CLM was first available but then repealed, the odds that teens would become new mothers increased. Births to teens younger than 18 were more responsive to availability of CLM than those to teens aged 18 or 19 or to women in their early twenties. The likelihood of becoming a mother increased where CLM was available in the years prior to its repeal. Teens were more responsive to information about availability of CLM about three years later than to knowing that it is available at the time of potential conception. To the extent that they reduce teen births CLM laws are socially desirable and states that still have CLM may be better off by not repealing the law.