Portland Public Schools, the state's largest school district by enrollment, currently serves 49,000 students. The district proudly states that it's enjoyed seven straight years of enrollment growth, which it has. It's not so forthcoming about its decades of enrollment shrinkage; today's PPS enrollment is lower than it was in 1923 -- the administration of Warren Harding! -- when the district enrolled 50,513 students. The district hit its high point in 1963, with 79,571 students, and its low point in 2008, with 46,046 students. No massive network of private schools has sprung up to siphon students away from PPS, and the city's population continues to grow (in the 1990s mainly by annexation, but since then through new construction), up 65% since 1963. So where are the children?
The answer? They're in Gresham.
After the 2010 census, Multnomah County remapped its four county commission districts to have equal population. "Equal population" does not mean "equal voters," as children count toward population. The four districts vary wildly in demographics: they average 121,000 voters each, but District 1 (the westside and inner southeast, entirely within PPS) has 137,000 voters and District 4 (Gresham, Fairview, and east county, nearly entirely outside PPS) has only 101,000 voters. Turn this statistic around and you see where the children are: District 1 has about 16,000 fewer children and about 12,000 fewer school-age children than the county average. District 4 has 20,000 more children and about 15,000 more school-age children than average. District 2 (north and northeast Portland, north of the Banfield Freeway, mostly in PPS) is also missing its children: it has 130,000 voters, so about 9,000 fewer children than the county average.
One consequence of the 30,000 missing Portland children is that PPS is, on the Oregon scale, a rich district. It receives the benefit of the property tax revenues from the city's growth without having the burden of educating more people. (The PacWest Center, for example, built in 1988, pays about $1 million/year just in school taxes.)
Portland's missing children are in other places besides Gresham, for instance, in the David Douglas School District (roughly I-205 east to 142nd Avenue and from NE Halsey south to the county line), where enrollment increased by 16% from 2003 to 2013. From 1990 to 2010 the share of households with children in David Douglas increased from 34% to 36%; the share in the rest of Multnomah County fell from 30% to 26%.
So that's where Portland's missing children are. Why are they there? That's a subject for another post; the short answer, I believe, is that Portland has priced and gentrified their parents out of the city.