The 1,000-student Allegheny Valley district in Pennsylvania boasts generations of alumni and a community so involved with the schools that high school graduation becomes an open celebration in downtown Springdale Borough. Yet the district hasn't asked for a tax increase in three years, and it is pushing out a message to older residents about…

This issue, the fourth in a series on demographic forces shaping U.S. public education, discusses how the aging of the population affects education. The first section, "Shades of Gray," discusses how as the population ages, schools may face tougher competition for public resources, noting how tensions have surfaced in one Florida county.…