Northwest Environment Watch in Seattle, Wash., isn't very big at 1,400 members and five staffers, but its reach is ambitious. In less than four years it has published five reports, including The Car in the City, Stuff, and the latest and perhaps most provocative, Misplaced Blame: The Real Roots of Population Growth, by Alan Durning, founder of the group, and Christopher Crowther, a research intern and graduate student in demography at the University of California, Berkeley. In searching for the main spurs to the area's population boom, the authors found the easy answers, the ones we heard during debates over welfare reform, far too easy. Teenage girls don't fall into a cycle of poverty because they have babies too young, they found; they're poor to begin with and often sexually abused. The result: "Women who live in poverty have about twice as many children, on average, as more affluent women." Making women poorer by denying them reasonable aid is punitive and self-defeating, the writers conclude. They also say the real causes of the region's growth are our half-hearted efforts to provide contraception and abortion help, generous government subsidies to new industries and new residents, and the continuation of too-liberal legal immigration. The 94-page softcover book is $9.95 from Northwest Environment Watch, 1402 Third Ave., Suite 1127, Seattle, WA 98101-2118 (206/447-1880).