Women experience a significant drop in income from employment after marriage in Germany, with earnings decreasing by an average of 20%, according to a study by Munich's IFO Institute and the University of Oslo.

The research, titled "The Marriage Earnings Gap," attributes this decline to reduced working hours or complete withdrawal from the workforce because of increased responsibilities. In contrast, men's earnings remain unchanged after marriage. 

The study, based on pension insurance data, found that income differences between men and women grow significantly after marriage, regardless of whether they have children. ''Our research shows that the income differences between men and women increase in marriage, regardless of the birth of children," said IFO researcher Elena Herold.

Though men's earnings remain stable, women's income declines steadily over several years. Herold explained that this drop is not solely due to marriage-related childbirth.

Even when that factor is removed, women's earnings still decrease by 20%, and when childbirth is included, the decline reaches nearly 50%.

The study also found that cohabitation does not produce the same financial impact. "For couples who lived together before marriage, we see no different effects than those who only move in together with the wedding," Herold said.

She suggested that the greater legal security provided by marriage likely encourages women to reduce their working hours.

The income decline is not due to lower wages but rather a reduction in work hours. According to the study, one in ten women stop working altogether after marriage, while the rest work about 20% fewer hours. This shift occurs gradually over several years.

Meanwhile, household work done by women increases by a similar proportion, even when child-rearing is excluded. The study found no similar changes among men.

A key reason for the reduction in working hours is the structure of the tax system. Herold noted that "a quarter of the reduction in income for wives can be attributed to the splitting of income between spouses."

Gender roles also play a significant role. "For women who grew up in East Germany before reunification, we see less negative effects than for women from West Germany," said Herold.

Women who grew up in former East Germany (GDR) — where the IFO said there were more "gender progressive norms" — were found to have had a lower drop in earnings in marriage than women who grew up in West Germany, where there were more traditional gender roles.

Edited by: Kieran Burke