Korea's baby boomers born between 1955 and 1964 will have a period of nearly 20 years when they live alone with their spouses after their children have left home, since the average life expectancy has risen and the number of children per family dwindled. 

The so-called "empty nest" period has risen to 19.4 years, compared to a mere 1.4 years for their parents' generation, estimates show.

The estimates were presented by Han Gyoung-hae, a professor of consumer and child studies at Seoul National University, at a forum hosted by the Korean Women's Development Institute on Monday. "Husbands and wives in the earlier generations had shorter empty nest periods after their children got married, because they had many children and their life expectancy was shorter," Han said. "But with changing family life cycles, baby boomers will live on their own for 19.4 years after their children get married." "They need to prepare and figure out how to live alone well," she added.

According to Statistics Korea, the ratio of elderly couples to all married households will increase from 39 percent in 2010 to 54.2 percent in 2030. As society ages, many people in late middle age will have to take care of their elderly parents.

In a survey of 88 people over 95 and their families in Seoul conducted by Han in 2009, the average ages of sons and daughters-in-law who supported them were 67 and 61.2. She warned this could become a more widespread phenomenon.