Pill, Patch or Shot? Subjective Expectations and Birth Control Choice

When choosing a contraception method, women base their decisions on their subjective expectations about the realizations of method-related outcomes. Examples of such outcomes include getting pregnant, contracting a sexually transmitted disease (STD) or experiencing side effects. By conducting a face-to-face survey, I have assembled a unique dataset on women’s subjective expectations regarding existing birth control methods. While respondents have, on average, expectations consistent with actual population outcomes, they exhibit substantial heterogeneity in their subjective beliefs, which emphasizes the need to rely on expectations data when conducting inference. I combine expectations data with observed choices to estimate a random utility model of birth control choice, without making any assumption about expectations. Effectiveness, protection against STDs and partner’s disapproval are found to be the most important factors in the decision process. I have also elicited respondents’ willingness to pay (WTP) for a hypothetical 100% effective birth control method. Remarkably, the median elicited WTP is very close to the estimated parameter for preferences toward pregnancy outcome expressed in dollars. The reported WTPs are incorporated directly in the estimation to fully account for preferences heterogeneity for getting pregnant.