"Discrimination against widows and divorced women appears to be a phenomenon of many countries, not just some traditional cultures," says Steven Kull, director of WorldPublicOpinion.org. "People in most countries, including developed ones, recognize there is at least some discrimination."
Poorer treatment may take a variety of forms. In less developed countries, women's rights and development experts have long noted that wherever the wife has trouble securing her property rights after her husband's death, the widow and her children can become impoverished--in extreme cases by being stripped of her land or goods and expelled from the household. Divorce laws that do not recognize the wife's labor as constituting an economic stake in the household can have the same result. In developed countries, since women live longer, gaps in a country's social safety net are more likely to affect women. In the United States, for example, poverty rates for widows and divorced or separated women are far above the average.
. . . South Korea has the largest majorities believing that widows (81%) and divorcees (82%) are mistreated in their country. Recently South Korea has enacted legal reforms advancing women's status, and in 2005 its high court granted women for the first time the right to claim an equal share in jointly owned family property. Jeong Han Wool of the East Asian Institute (Seoul) adds: "Up until this year Korea employed a family registry system under which the status of "widow or divorcee" could cause some complications." Such changes may well have raised the salience of the issue in the minds of Koreans.
There is lots more information available on the WPO write-up, including a link to the full .pdf version of their findings. The blog The Grand Narrative has much more on gender issues and sexuality in South Korea, of particular interest here being this post and this post from January on, among other things, the short-lived Ministry of Gender Equality and Family.