What are the consequences of religious exemptions of antidiscrimination laws? And what are the normative implications of these consequences? These questions are currently at the center of a heated debate balancing religious freedom and civil rights. Opponents of religious exemptions from antidiscrimination laws argue that granting exemptions would increase sexual orientation discrimination. Proponents of religious exemptions argue that religious objectors are a small minority and that their exemption would not meaningfully increase discrimination against same-sex couples. The troubling aspect of this debate is that none of the parties rely on hard data. Particularly missing are data on the effects of exemptions granted in Supreme Court decisions, an issue that the Court has addressed repeatedly in recent years--and is set to do so once again this term, in Fulton v. City of Philadelphia. This Article intervenes in the debate based on the results of a large-scale field experiment that measured the effect of Masterpiece Cakeshop v. Colorado Civil Rights Commission on the ability of same-sex couples to receive services in the wedding market, as compared to opposite-sex couples. The field experiment revealed that after Masterpiece Cakeshop, vendors were less willing to provide wedding services to same-sex couples than to opposite-sex couples. This trend was true even for vendors that provided services to same-sex couples prior to the Masterpiece Cakeshop decision. Following Masterpiece Cakeshop, the odds that same-sex couples would experience discrimination from wedding vendors are estimated to be between 61% and 85%. These results have several implications for the debate on religious exemptions. First, they discredit the argument that the effects of religious exemptions are negligible, making clear that exemptions will promote further discrimination. Second, the results complicate the conventional portrait of religious objection as fixed (and therefore unyielding to change), showing instead that the demand for discrimination is elastic and shaped by social constructions, even without coercion or sanctions. These negative effects of Masterpiece Cakeshop bear on both litigation--showing that antidiscrimination laws are necessary to further states' compelling interest in securing equality--and in legislation--providing guidance for legislatures on whether and how to enact religious exemptions from antidiscrimination laws. Finally, the troubling consequences of Masterpiece Cakeshop require the Supreme Court to proceed with great care as it sets out to decide Fulton v. City of Philadelphia and any other future cases raising ostensible conflicts between religion and anti-discrimination law. However the Court decides to resolve the constitutional issue at hand, it must take into account that even a deliberately narrow and case-specific exemption might have a significant negative impact on the market and its customers. [ABSTRACT FROM AUTHOR]