A new report from the University of Minnesota Institute on Race and Poverty (IRP) says most charter schools do more harm than good. The study concludes that Twin Cities-area charter students do worse academically than their public school peers. And the report argues that charters, with large percentages of lower-income students of color, deepen racial and economic school segregation.

Much of the information is not new. Previous studies have questioned whether charters do a better job academically than their public school counterparts, while others laud their effectiveness. Still, the report raises important questions and provides data for discussion as state lawmakers consider charter and other school policy questions during the 2009 session.

IRP researchers said that only 24 percent of elementary school charters in the Twin Cities performed better than expected on a state test, given their rates of poverty. But 54 percent of traditional school pupils performed better than expected under the same circumstances. And 79 percent of Choice is Yours schools -- which allow Minneapolis students to transfer to suburban schools -- had those outcomes.

As charter advocates argue, there are various ways to assess test score data and other student achievement research. The IRP study analyzed one set of 2007-08 state reading and math test scores. Other studies have found that students make more progress over time in some charter and other alternative programs.

A legislative auditor report earlier this year said charters posted lower test scores statewide than traditional schools. But when schools with similar poverty, mobility and students of color were compared, that study found district and charter schools performed at similar levels. In addition, some segregated and lower-income charters have done well academically. Harvest Preparatory School in Minneapolis, with mostly African-American students, and Tarek ibn Ziyad Academy in Inver Grove Heights, with mostly Muslim students, met or exceeded state testing goals.

This latest examination of local charters comes at a good time. The legislative auditor recommended that charter schools need more oversight and clarification about the roles of their sponsors. As a result, a group of state lawmakers is currently meeting and holding hearings about improving charter school laws.

The IRP study raises concerns that both the charter school group and other legislative education committees should consider. Questions include: Should charters be subject to some student outcome requirements? What is the value of charters or other alternative programs that keep students in school who might otherwise drop out? Some charters and traditional public schools are highly successful with low-income students. What prevents those models from being replicated? Should the state do something beyond current voluntary efforts to encourage school desegregation? And because parent surveys show high satisfaction with charters, how can or should government reconcile those family choices with academic standards?

The IRP and other studies provide good grist for answering those questions and making decisions about charter school rules in the future.