The US Supreme Court’s upcoming affirmative action decision—which many legal experts expect will limit or end the consideration of an applicant’s race in college admissions—would likely immediately hinder college and universities’ ability to maintain, let alone increase, the racial and ethnic diversity of their student bodies.

Research on schools in states that have eliminated affirmative action suggests no other single admissions policy will produce current levels of racial and ethnic diversity on its own. What admissions policies have been enacted in states where affirmative action has already been banned? And what effect have those policies had on student racial diversity?

The effects of banning affirmative action on school diversity

In states that have eliminated affirmative action, studies have consistently found declines in the admission and enrollment of Black, Latinx, and Indigenous people. These declines are especially concentrated in selective and flagship institutions.

• The passage of California’s Proposition 209 in 1996 resulted in a 12 percent decline (PDF) in underrepresented groups across the whole University of California (UC) system . UC Berkley and UCLA experienced the biggest effects, with a 60 percent drop (PDF) in Black, Latinx, and Indigenous students.
• In 2006, after Michigan passed Proposal 2 (PDF), which banned race-conscious admissions, Black undergraduate enrollment at the University of Michigan dropped nearly by half—from 7 percent in 2006 to 4 percent in 2021 (PDF).
• In the first class admitted to the University of Washington after the state banned the use of race in admissions, Black, Latinx, and Native American enrollment made up 7 percent of the entering class, compared with 8.2 percent the year before the ban.

Evidence shows diversity in higher education improves learning outcomes for all students, and the benefits extend beyond graduation. A ban could not only negatively affect students of color, who would be less likely to attend selective institutions that usually have more resources and higher graduation rates, but could also prevent other students at these universities from benefiting from the perspectives and experiences that having a more diverse class brings.

Race-neutral admissions policies may help with diversity, but none alone are equivalent to affirmative action

Simulations that measure the consequences of banning affirmative action and the effectiveness of race-neutral policies find that although alternatives may mitigate the effects of the ban, they will not fully make up for the loss of racial diversity on their own. However, if the use of race is prohibited in college admissions, the following approaches would likely be most adopted.

1. Class-based affirmative action

A frequently discussed race-neutral admissions policy is a class-based admissions practice. Under this approach, greater weight is given to applicants from less affluent socioeconomic backgrounds to recognize those students may not have had the same resources and educational opportunities as wealthier students. Black and Latinx households have disproportionally lower incomes because of structural barriers, so applying a greater weight to an applicant’s income status theoretically could produce a more racially diverse cohort of students.

Multiple statistical models of this approach found absent other changes to the current admissions process, class-based admissions on its own would not provide similar levels of diversity as race-based admissions. In its amicus brief, the University of Michigan went a step further, saying class-based admissions don’t increase racial diversity, and using it as “the sole means to increase nonwhite enrollment can exacerbate stereotypes rather than alleviating them.” (PDF)

Because there are more white people with low incomes than racially underrepresented people with low incomes, and because people of color with low incomes also face systemic racism that further disadvantages them in the education system, class-based affirmative action would likely not lead to racial diversity at the same levels as race-based affirmative action.

2. Percentage plans

After affirmative action was banned in California, Texas, and Florida, each state implemented percentage plans (PDF) under which a certain percentage of the top students from a high school’s graduating class would receive automatic admission to state universities. Texas’s percentage plan, developed by a special task force of the state legislature, was adopted to combat the effects of the Hopwood ruling on diversity (PDF). The idea was that by admitting students from various high schools around the state, the state’s universities would be more representative of Texas’s population, leading to greater diversity.

Although these policies helped increase diversity at some schools, they were less effective than race-based admissions policies in increasing Black and Latinx student enrollment because of Black and Latinx underrepresentation in the top percentages of high school classes and the fact that many of the racially underrepresented students at the top of their classes likely would have been admitted without the automatic admission plan.

Additionally, in Texas, studies show that rebounds in the amount of racially or ethnically underrepresented students at state universities after the elimination of affirmative action are more attributable to the large increases of Latinx and Black people in the overall population than the state’s top percentage plan.

3. Targeted recruitment

Data show application rates of underrepresented racial and ethnic groups to selective institutions are not representative of their state’s demographic composition. These students of color with similar qualifications as white students are also less likely to apply to more-selective schools, even when eligible for automatic admission.

Increased recruitment in areas with greater racial diversity can help inform prospective students about the application process and encourage them to apply but may not offset declines that occurred after affirmative action bans alone.

For example, Texas A&M and the University of Texas at Austin created partnership programs with underrepresented schools to recruit and provide financial aid and support to a select number of students. But even with this program and automated admission, those eligible for the scholarships and the top percentage plan were still less likely to enroll in these more selective universities relative to other high school students.

4. Ending legacy preferences in admissions

The systemic exclusion of students of color from higher education means white students benefit most from legacy preferences in admissions. Many highly selective schools admit more legacy students than Black and Latinx applicants, and the rate of admission for legacies is more than three times higher than for nonlegacy applicants.

Ending legacy admissions could help make the higher education admission process more equitable. When Johns Hopkins University eliminated legacy preferences in 2014, the percentage of first-generation students increased by approximately 10 percent, and the percentage of Pell-eligible students increased by about 7 percent between 2013 and 2021.

5. Test-free and -optional admissions policies

Though standardized tests for college admission are often found to benefit wealthy, white students most, research on the role of test-optional policies in increasing the racial diversity of applicants is inconclusive. However, a study on the institutions that adopted the policy found the percentage of Black, Latinx, and Indigenous students and the percentage of Pell-eligible students increased slightly at test-optional institutions, compared with similar schools that still required SAT or ACT scores. Making tests optional or eliminating them could help selective institutions remove one barrier to students of color applying and being admitted.

Research suggests colleges and universities—particularly selective ones—would experience a decrease in racial and ethnic diversity among their students if the Supreme Court ends race-based affirmative action because no single race-neutral admission policy has the same effect as race-conscious admissions. If overturned, returning to current diversity levels would require a commitment to adopting a combination of the strategies above, innovating these strategies, or developing new ones.

In the meantime, better national data on the admissions process will be critical to understanding the effectiveness of race-neutral policies.