Impact of Home Ovulation Tests on Marital Sexual Life in Singapore: Evidence from a Randomized Controlled Trial

Abstract

This paper investigates the impact of home ovulation tests on the sexual lives of Singaporean married couples. Information about time of ovulation allows couples to adjust both the volume and timing of sexual activity to maximize chances of achieving their fertility ideals. In addition, when couples’ fertility ideals diverge, behavioural changes are more likely to be aligned with wives’ ideals due to informational asymmetry. Evidence from a randomized controlled trial based on diary data collected biweekly over 14 weeks from 657 married women aged 25-34 suggests that among couples whose fertility ideals were not achieved, access to ovulation tests did not lead to a lower volume of sex. These couples were more likely to have sex on days of positive test results but did not avoid sex when results were negative. There is some support for the hypothesis that informational asymmetry favors wives’ fertility ideals. Higher access to home ovulation tests increases the probability that sexual activity falls within the fertile window among married couples who have not achieved their fertility ideals, and may reduce waiting time to pregnancy in low-fertility societies.