Korea's working-age population is dwindling faster than that of other OECD countries, according to a study.

Korea's population between 15 and 64 began decreasing in 2017 after it peaked at 37.63 million in 2016, according to the study by Prof. Oh Min-hong of Donga University. The study projects it as dwindling from 37.02 million in 2017 to 34.08 million in 2027 and to 30.02 million in 2037, a decrease of over 18 percent.

But in other OECD member countries the working-age population is expected to keep rising 0.4 percent until 2027 and dwindle a mere 0.1 percent until 2037, according to an OECD projection. That is because while the population under 40 will dwindle, the population in their 40s and 50s will increase 0.5 percent and 1.4 percent.

In Korea, the entire population from 20 to 50 is expected to dwindle 18 to 33 percent. The sharpest contrast can be seen in the increase rate of the elderly population, which is projected at a massive 118.6 percent in Korea by 2037 but just 47.4 percent in the rest of the economic bloc. This will reduce the working-age population here to just 58.1 percent of the total by 2037.

"The population is shrinking slowly in other OECD countries, and neighboring age groups can make up for a population drop in a shrinking group," Oh said. "But in Korea, most of the working population is dwindling at the same time, so the slack can't be taken up by other groups."

The average retirement age in Korea from the main job of a lifetime has shrunk only slightly, from 49.2 in 2011 to 49.1 in 2016, according to the Korea Employment Information Service.

Once they retire many people find part-time or odd jobs, so about 65.9 percent of people aged between 55 and 64 are still working, compared to the OECD average of 58.1 percent.

"We'll be hit by the impact of an aging society soon," Oh said. "We urgently need to reform the labor market and employment structure to suit a super-aging population."

