Advocates of Pennsylvania’s two backdoor voucher programs, which provide public tax credits for private contributions to private schools, say that they help poor kids who are trapped in poorly performing public schools.

Well, some of the contributions do so. But as demonstrated by the Keystone Crossroads, a left-leaning policy think tank in Harrisburg, some of the money helps kids who are “trapped” in some of the state’s toniest neighborhoods amid some of its best-performing public schools.

Under the Educational Improvement Tax Credit and Opportunity Scholarship Tax Credit programs, the state awards tax credits to companies that contribute to nonprofit scholarship organizations, most of which are attached to private schools, including religious and secular institutions. The tax credit is 100 percent for the first $10,000, 75 percent for anything above that, and 90 percent for maintaining the contributions for two consecutive years. Credits are capped at $200,000 a year per donor, for two years.

The new state budget increased the total amount of the tax credits to $240 million per year from $210 million a year.

Leaders of the Republican legislative majorities wanted to increase the amount this year by $100 million and automatically increase it every year relative to an inflation index.

The Keystone study demonstrates why better standards are needed before the contribution amounts increase again, and why they never should be subject to automatic increase without annual reviews.

The programs unquestionably help many needy students get into better schools. But that is not exclusively the case.

Keystone compared the contributions received by 151 schools that administer their own EITC/OSTC programs, and compared it with the demographic data that the schools report for other purposes to the state Department of Education.

It found that 57 of those schools reported that they had not enrolled any low-income students, and that another 15 reported low-income enrollment of less than 5 percent.

The Shipley School in Bryn Mawr, for example, reported zero low-income enrollment and $500,000 in EITC/OSTC contributions eligible for publicly funded tax credits.

Whereas the Gesu School in North Philadelphia reported 80 percent low-income enrollment and $816,000 in tax credit-based contributions.

The state administers the tax credit programs but does not require the schools to calculate the number of low-income students who receive the scholarships.

Both tax-credit programs inherently are controversial because they use public resources to cover private contributions to private, often religious schools.

Since the objective of the programs is supposed to be providing alternatives to students who need but can’t afford them, lawmakers should require detailed data on the family income status of scholarship recipients.

Eligibility levels are generous. Families of four with incomes up to $116,000 are eligible. Although families with that income might not be able to afford $23,000 a year for high school tuition, the schools that charge those rates often are in proximity to outstanding public schools, rather than distressed and poorly performing schools from which the programs are supposed to provide relief.

Before lawmakers act again to divert more public money to private institutions in the form of tax credits, they should make sure that the public has comprehensive, detailed information on the institutions and students that benefit from the programs.