Recent research on statewide voucher programs in Louisiana and Indiana has found that public school students that received vouchers to attend private schools subsequently scored lower on reading and math tests compared to similar students that remained in public schools. The magnitudes of the negative impacts were large. A case to use taxpayer funds to send children of low-income parents to private schools is based on an expectation that the outcome will be positive. These recent findings point in the other direction. More needs to be known about long-term outcomes from these recently implemented voucher programs to make the case that they are a good investment of public funds. As well, we need to know if private schools would up their game in a scenario in which their performance with voucher students is reported publicly and subject to both regulatory and market accountability. This report explores possible reasons why negative effects have been found in test scores studying publicly funded voucher programs in both Louisiana and Indiana. The following questions regarding the negative findings in recent studies of voucher programs in Louisiana and Indiana are addressed: (1) Did the design of the research studies affect the results?; (2) Did the structure of the programs contribute to the negative findings?; and (3) Did the quality of the public schools against which private schools were being compared contribute to the negative outcomes? Contains endnotes.