Behind-the-counter, but Over-the-border? The Assessment of the Spillover Effect of Increased Availability of Emergency Contraception in Washington on Neighboring States

Emergency contraception (EC), that gained FDA's approval in the late 1990s as a prescription medicine, may effectively prevent unwanted pregnancy if taken promptly after an unprotected sexual intercourse. Because EC efficacy is inversely related to the duration between intercourse and the time it is taken, the prescription requirements can make it less effective. Washington was the first state to loosen up the prescription requirements making EC available behind-the-counter at pharmacies to women of any age in 1998. I hypothesize that the increased availability of EC affects fertility rates beyond the borders of the state that allows it. Using the difference-in-difference methodology and 1991-2005 county level data, I find that increased access to EC is associated with a substantial and statistically significant 5-7% decrease in abortion rates and 2% decrease in pregnancy rates in Washington counties that had access to EC without a prescription within 10 miles. As expected, the effect becomes numerically smaller and statistically weaker with an increase in travel distance. I find some evidence in support of the spillover effects in Idaho, but not Oregon. After accounting for changes in the availability of abortion services, the decrease in fertility rates in "treated" Idaho counties is rather small and models lack sufficient power to detect it.