Today, total illiteracy is less than 1 percent although functional illiteracy -- defined as lacking the reading and writing skills to function in a modern society -- is higher.
Thanks to an unofficial policy of "social promotion" that grants students passing grades regardless of academic performance, graduates can possess both a high-school diploma and functional illiteracy.
There are other societal and economic costs as well, including public welfare for impoverished adults who are set back by functional illiteracy; three-quarters of welfare recipients fall into this category.
