Korea has the widest gap between the earnings of men and women in the 30 OECD member states. According to an OECD report released Thursday, Korean men earned on average 38 percent more than women as of last year. The gap is more than double the OECD average of 18.8 percent.

Japan came second with a gap of 33 percent, followed by Germany (23 percent), Austria (22 percent), and the U.K. and Canada (21 percent).

Korea came fourth with 30 percent in terms of the employment gap between men and women after Turkey (51 percent), Mexico (46 percent), and Greece (32 percent).

The birthrate is also the smallest in the OECD at 1.08, far below the average of 1.64. The average age of Korean women at first childbirth is 29.1, the fifth oldest in the OECD members and 1.3 years older than the average. And the teenage birthrate, or births per 1,000 South Korean girls aged 15-19, was the lowest at 3.5, while that of the U.S. was the highest at 50.3.

The ratio of out-of-wedlock births to total births for Korea was also the lowest at 1.3 percent, while Iceland's was the highest at 65.6 percent.