Abstract: The school voucher program encourages households to consider private schools as additional options. Policymakers and researchers have observed increasing competition between public and private schools, as public schools strive to retain students by improving their educational quality and performance in response to the voucher-driven shift in school choices. While most studies have documented the effects of means-tested voucher programs on public school test scores, relatively few have examined universal voucher programs, which have become more prevalent since 2020. This paper examines the recent universal school voucher programs by analyzing their impact on public schools' educational performance (test scores) and capital expenditures through both cross-state and within-state analyses. Using data from the National Longitudinal School Database (NLSD) and the Stanford Education Data Archive (SEDA), we employ a Generalized Difference-in-Differences (GDD) approach, combining a staggered Difference-in-Differences (DD) design with a continuous treatment variable in our cross-state analysis. We also employ a dosage Difference-in-Differences approach in our within-state analysis. Preliminary within-state results show a significant increase in public school test scores in Arizona and Florida, with math scores rising by 5.5% and 5.7%, respectively. In contrast, Ohio experienced a 2.5% decline in test scores. Analysis of additional test scores and capital expenditures is currently underway.