Effects of Intensive Longitudinal Data Collection on Pregnancy & Contraceptive Use

We use an experiment based on the Relationship Dynamics and Social Life (RDSL) study of sexual behavior, pregnancy, and contraceptive use to investigate whether participation in weekly self-reports over one year result in differential effects on related behaviors and attitudes, compared to participation in a one-time follow-up interview requiring retrospective self-reporting for the prior year. 

We randomly assigned 200 subjects to either a control group or a journal group. All subjects were interviewed at the beginning of the study (baseline interview) and 12 months later (closeout interview). Subjects in the journal group also completed a five-minute web- or phone-based survey every week during the 12-month study period. 

We found no statistically significant difference in pregnancy rates across the two groups at closeout. Contrary to our expectation, the control group experienced a slightly larger increase in having ever used a contraceptive method, although this was mainly due to increases in the least effective methods, such as condoms and withdrawal. 

Respondents in the weekly interview group became slightly more positive toward childbearing in terms of one specific attitude measure, but not for the vast majority of measures. 

We conclude that intensive longitudinal data collection does not appear to have a large or consistent impact on respondents' pregnancy, contraceptive use, or related attitudes, relative to the more standard longitudinal approach.

Purchase full article at:   http://goo.gl/faEuin

By:  Barber JS1, Gatny HH1, Kusunoki Y1, Schulz P1.

• 1Institute for Social Research (http://home.isr.umich.edu/), University of Michigan, Ann Arbor, MI USA. 
• Int J Soc Res Methodol. 2016 Mar 1;19(2):205-222. Epub 2014 Dec 1.

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Race-Ethnic Differences in the Non-Marital Fertility Rates in 2006–2010

Research in the 1980s pointed to the lower marriage rates of blacks as an important factor contributing to race differences in non-marital fertility. Our analyses update and extend this prior work to investigate whether cohabitation has become an important contributor to this variation. We use data from the 2006–2010 National Survey of Family Growth (NSFG) and to identify the relative contribution of population composition (i.e. percent sexually active single and percent cohabiting) versus rates (pregnancy rates, post-conception marriage rates) to race-ethnic variation in non-marital fertility rates (N=7,428). We find that the pregnancy rate among single (not cohabiting) women is the biggest contributor to race-ethnic variation in the non-marital fertility rate and that contraceptive use patterns among racial minorities explains the majority of the race-ethnic differences in pregnancy rates...

The main goal of this paper was to examine the relative importance of relationship status, pregnancy rates, and post-conception marriage to race-ethnic differences in non-marital fertility in 2006–2010. This effort represents an update of prior work and an extension to incorporate cohabitation and consider fertility patterns among Hispanics. Our analysis provides us with several findings. First, today variation in sexual activity and in post-conception marriage contributes little to racial differences in non-marital fertility. Second, cohabitation plays a smaller role than we anticipated. Even among U.S.-born Hispanics, pregnancy rates among sexually active singles were as important as rates among cohabitors, but for blacks and foreign-born Hispanics cohabitation clearly has a secondary role.

These findings may be in some ways surprising given all the attention demographers have paid to the importance of cohabitation for non-marital fertility trends and a common perception that cohabitation might serve as an alternative to marriage for minority women, especially Hispanic women. Yet, over the past 30 years as the non-marital fertility rates have been rising for whites, they have not increased for blacks or Hispanics. The increase in non-marital fertility over this time was largely due to increases in cohabitation among white women (Raley 2001), which greatly diminished race-ethnic variation in non-marital sexual activity. Declines in post-conception marriage led to rises in non-marital fertility among both whites and blacks in earlier parts of the century (England, Wu, and Shafer 2013), but postmarital conception was already rare among blacks by 1980. Since then, whites and Hispanics have been catching up (Bachu 1999) so that today race-ethnic differentials in post-conception marriage are relatively small (Lichter 2012). As race-ethnic differences in sexual activity and post-conception marriage diminished, differences in fertile pregnancy rates became the most important factor suppressing white non-marital births.

Today black-white differences in the non-marital fertility rates are driven largely by differences in the pregnancy rates among sexually active singles. Our analyses suggest these differences are largely due to patterns of contraceptive use. Lower abortion rates among black and Hispanic unmarried pregnant women might contribute somewhat to their higher fertile pregnancy rates, but variation in contraceptive use is more than sufficient to explain race-ethnic differences...

Below:  Fertile Pregnancy Rates and Estimated Pregnancy Rates by Race-Ethnicity and Relationship Status (per 1,000 women)

Panel A: Cohabiting Women

Pane B: Single Women

Full article at: http://goo.gl/q8XAeM

By: Yujin Kim and R. Kelly Raley

University of Texas at Austin

  

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