If private school vouchers are offered to all parents living in poor districts (as opposed to being offered only to low-income families), this would lessen income segregation across school districts. That's because many families presently stretch their budgets to pay inflated housing prices in good public school districts. If a middle-income family living in such a district chooses to switch to a private school with the help of a voucher, that family could then afford to move to a worse school district and get more house for its money. So argues Tom Nechyba of Duke University and the National Bureau of Economic Research in "The Unintended Benefits of Private School Choice," which appears in the June 2002 issue of The School Choice Advocate, the newsletter of the Milton and Rose B. Friedman Foundation, at http://www.friedmanfoundation.org/resources/publications/advocate/june2002advocate.pdf