This year it was that time again on March 17th: In Munich, the tram with the words "Next stop Equal Pay" drove through the city, in front of the town hall in Berlin's Tiergarten district a flag was hoisted to indicate the pay gap between men and Point out women.

It has already become a tradition that associations, parties and sometimes just individual people demonstrate on Equal Pay Day who are bothered by the unequal earnings.

This article comes from the "WirtschaftsWoche".

In purely mathematical terms, women work without pay until Equal Pay Day, provided they receive the same hourly wages as the men.

But that is still not the case in Germany.

According to the Federal Statistical Office, the earnings gap was 20 percent last year.

That seems dramatic.

But is that really it?

The 20 percent only indicate the unadjusted pay gap.

Put simply, it compares the average earnings of all employees.

It is also so big because women more often work part-time or in poorly paid industries or are less ambitious in their own careers, explains Christine Seibel, compensation expert at the Korn Ferry management consultancy.

The wage gap increases over the years

According to figures from the labor force survey in 2018, almost every second woman between the ages of 20 and 64 worked part-time, for example because she is looking after children or relatives in need of care.

For men, however, it was only nine percent.

The German Institute for Economic Research (DIW) also confirms the influence of part-time work in a study.

There the economists found that the wage gap between women and men increases with age.

At the age of 25 to 30 it is around nine percent, after which it increases continuously up to the age of 49 and levels off at 28 percent.

The reason: While the salary of men continues to rise from the age of 30, that of women stagnates.

And that's also because women often have a child and decide to only work part-time.

For women who work full-time, however, the wage develops almost identically to that of men.

This is most extreme in industries in which employees receive a high variable salary component, such as insurance companies, banks or other financial service providers.

Between the ages of 25 and 27, both genders work more than 90 percent full-time, so they earn the same amount.

At the age of 34, a third of women only work part-time and receive 25 percent less salary.

So incentives are needed to do more for a gender-equitable world of work.

In addition, the current spouse splitting is still rewarding when the wife stays at home.

Because so far women have to pay the maximum marginal tax rate of their spouse on the first euro they earn.

Therefore, on average, they pay a higher proportion of their income in taxes.

Men, on the other hand, have to cede less taxes due to spouse splitting.