New research shows that where children live matters deeply in whether they prosper as adults. On Monday the Census Bureau, in collaboration with researchers at Harvard and Brown, published nationwide data that will make it possible to pinpoint — down to the census tract, a level relevant to individual families — where children of all backgrounds have the best shot at getting ahead. Believing this, officials in the Seattle Housing Authority are offering families with housing vouchers extra rent money and help to find a home in these prosperous areas.