Users Beware: Variable Effects of Parenthood on Happiness Within and Across International Datasets

Researchers have begun assessing differences in well-being among parents versus non-parents using a cross-national comparative approach. Given the availability of multiple major datasets, a systematic methodological study isolating the effects of data choice would be helpful. To accomplish this objective, we draw upon two major datasets (European Social Survey and International Social Survey Programme) and we devise and implement a uniquely controlled method on five fronts by holding time, outcome measurement, parenthood operationalization, geographic sampling, and set of covariates constant. Our design features four distinct observations for each of 11 European countries (two from the 2006 and 2008 ESS, two from the 2007 and 2008 ISSP; 44 cross sections, N = 57,539). Employing both fixed- and random-effects approaches, we demonstrate that choice of major dataset (ISSP or ESS) and choice between contemporaneous cross-sections both contribute strikingly to the estimates of parenthood on happiness. In fact, effect variances at the cross-sectional, dataset and country levels are all significant and are not statistically different. We conclude by discussing several limitations of our analyses and implications for parenthood researchers.