Multiple-Partner Fertility: Variation Across Measurement Approaches

Abstract

Contemporary US families are characterized by high levels of complexity but measuring complexity, such as multiple-partner fertility (MPF), can be difficult. Scholars generally use indirect methods rather than direct items to measure MPF due to data limitations. The redesigned 2014 Survey of Income and Program Participation (SIPP) and the 2011–2015 Cycle of the National Survey of Family Growth (NSFG) provide a unique opportunity to evaluate different measurement approaches. We document variation in prevalence estimates of MPF among women aged 15–44 across approaches and datasets. Overall, our findings suggest that 20–25% of mothers experience MPF. Direct measures of MPF produce lower prevalence estimates compared to semi-direct and indirect approaches, pointing to the possibility of social desirability bias. Moreover, direct measures seem to perform particularly poorly for less advantaged women. Further, variation in identifying MPF has implications for its association with other behaviors and outcomes. We conclude with a discussion of these findings and make recommendations for future data collection and research endeavors.