Effects of Working Hours Distribution on Fertility: A Pooled Time-Series Analysis of 19 OECD Countries

Abstract

This study conducted a pooled time-series analysis using data from 19 OECD countries from 2000 to 2018 to comprehensively explore the effect of working hours on fertility. Building on the understanding of the relationship between working hours and fertility that has been established by previous studies, we analyzed how the distribution and the duration of working hours affect fertility, with particular attention to differences between women and men. The main results of the analysis are as follows. First, with other factors controlled for, total working hours have a negative effect on fertility. Second, the proportion of workers who work less than 40 hours per week has a greater effect on reducing the birth rate than total working hours alone. However, an increase in ultra-short-hour work (fewer than 20 hours per week) has no significant effect on the birth rate. Third, the distribution of working hours for both women and men has a similar effect on the fertility rate. Fourth, the distribution of working hours at the intermediate level (20 to 40 hours per week) fully mediates the effect of working hours on fertility. These results indicate that, in terms of the effect on fertility, policies on working hours should prioritize reducing overall working hours for all workers rather than simply increasing the number of part-time jobs or offering targeted time-support measures for women. This suggests that the current trend in South Korea's labor market policy, which continues to favors long working hours and supports a flexible application of the the existing 40-hour workweek with a 52-hour cap, may negatively affect fertility.