In the 2017-18 school year, 18% of New York students opted out of a mandated state assessment test. On Long Island, that number was closer to 50% of students opting out of one or more tests. The implications of this phenomenon are far-reaching, but unknown. This study seeks to better understand both who opts out and the potential impact of opt out on future academic performance. Using secondary data, it first identifies if the decision to opt out of the New York State 8th Grade Mathematics Assessment Test varied by race, gender, socioeconomic status, special education classification, or prior GPA during the 2017-2018 school year. Then, the study analyzes how the decision to opt out related to students' subsequent scores on the New York State Algebra Regents Exam taken in the following school year. Results show that White and Female students opt out at higher rates than their racial and gender counterparts, but there is no effect of opting out on later test performance. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]