Working mothers who earn more tend to have more babies than those with lower pay, a report showed Sunday.

Women working in the public sector, including civil servants, also had more children than their private-sector counterparts, it added.

The Korea Institute for Health and Social Affairs said the average fertility rate of women with a monthly salary of more than 2 million won ($1,860) was higher than of those who earn less than 1 million won, in an analysis of the correlation between birthrates and women’s job conditions.

The state-run research institute said it utilized existing surveys on the country’s job markets conducted from 1998 to 2008 by a labor panel. About 5,000 households participated in the surveys, it said.

When looking into the relationship between women’s working conditions and their chances of having a second child, the report revealed that part-timers with college degrees were more likely to have second children than regular workers.

“The fertility rate of women with higher incomes was higher while women who pursue careers tend to have fewer babies,” the institute said a day before it holds a symposium on low birthrates and an aging society on Monday in Seoul.

“To improve the birthrate, (the government) needs to implement practical policies to balance work and family, and lead a fundamental change in (social) culture,” it said.

Women working in the private sector had a tendency of having fewer children for fear of losing their jobs when compared to those in the public sector with higher levels of job security.

The report showed that women in their 30s working in the public sector had an average 0.67 more children than those in the private sector.

“(The study) showed statistically that the fear of childbirth interrupting women’s careers had a big impact on bringing down the fertility rate,” said Myongji University professor Woo Suk-jin, who participated in the research.

By Cho Chung-un (christory@heraldcorp.com)