COMMON CARRIERS. The Fall 2002 Journal of Economic Perspectives offers two papers on the economics of school vouchers. In "School Vouchers: A Critical View," Helen F. Ladd identifies a self-selection effect that she views as undesirable: to the extent that parents would use vouchers to improve the quality of their childrens' classmates, the lowest-quality students would be left with each other, and no examples of higher-quality classmates to emulate (or, in the Superintendent's jaundiced view, to beat up.) Derek Neal, in "How Vouchers Could Change the Market for Education," assesses a number of topics, including self-selection effects in Catholic schools ("many families and students who do not match well with either the religious culture or educational philosophy of Catholic schools would likely receive a voucher. These students would not benefit from access to Catholic schools ..."), changes in the labor market for teachers ("public school personnel policies are inefficient" with particular emphasis on time- and credentials- based salary schedules independent of field,) and the capital loss that vouchers would impose on homeowners in the best government school districts. Neal reports on some not-yet-published research on ability-based vouchers in which the most able students would receive a lower value voucher. His conclusion: "not possible to implement."

Both papers view the greater separation of students by aptitude or attitude toward schooling as a bad. Perhaps that's a topic for cross-disciplinary research. Should any good student have to sacrifice some of his education in order to provide a positive example to others less motivated? What are the incentives to parents to let their childrens' bad behavior slide, not to mention to actively enable it, never mind the consequences to that kid and the others in his class?