Viewpoint diversity is a critical component of an intellectually robust academic culture. Without an array of competing scholarly views and theories, scholars risk falling prey to confirmation bias, motivated reasoning, and conformity. Viewpoint homogeneity among faculty risks narrowing discourse to a few choice topics and approaches, and bucking conformity becomes more difficult the greater the imbalance. All of these tendencies work against the truth-seeking mission of the university. 

In recent years, commentators from both within and outside of the academy have expressed growing concern that universities are now overwhelmingly dominated by left-leaning faculty, particularly relative to the general American population (in which only 25% of people consider themselves “liberal”). Notably, political asymmetry within the academy is not by itself an indication of bias in the pipeline if, for instance, liberals are more drawn to academic careers than conservatives. However, if the asymmetry is wider now than in the past, it might be important to examine why that is the case, particularly given that academics rely on peer evaluation for selection and promotion. Moreover, critics allege that this imbalance of political diversity leads legitimate viewpoints and lines of inquiry to receive insufficient attention, not on the basis of merit but on palatability. 

While critics of the academic status quo sometimes cite ratios of Democrats to Republicans as evidence that conservative faculty are an “endangered species” on university campuses, others see such allegations as methodologically unsound exaggerations that provoke unwarranted attacks on higher education. 

To make sense of these competing claims about faculty political diversity, we undertook a critical review of recent faculty surveys and other research that assessed the political ideologies and party affiliations of faculty in the United States. 

This work is descriptive in nature. For those concerned with viewpoint diversity in academia — whether for or against any particular conceptualization of viewpoint diversity — establishing a shared understanding of the current distribution of faculty political leanings is a key foundation for an informed discussion on the topic.

Key findings include: 

• Studies of faculty political diversity consistently find that left-leaning faculty outnumber right-leaning faculty. 
• Since 2012, studies have found widely varying ratios of liberal to conservative faculty, ranging between 2:1 and 82:1. This shows substantial variability across studies in the magnitude of the political imbalance. Still, nearly all studies point in the same direction: liberal faculty outnumber conservative faculty. 
• There is considerable variation across academic disciplines, with greater shares of left-leaning faculty found in the humanities and some social sciences compared to economics, business, political science, and STEM fields. 
• Across studies, sizable minorities of faculty identified as moderate or were unaffiliated with a major political party. 
• A narrow focus on ratios of only Democrats to Republicans (or liberals to conservatives) obscures the true distribution of political viewpoints in academia by overlooking faculty who are moderate or apolitical and may exacerbate perceptions of polarization within the academy.
• There are notable limitations to much of the extant research: low response rates, unmeasured non-response bias, imperfect measures of political leaning, and the focus on only particular subsets of faculty (e.g., those within elite institutions or specific disciplinary areas), rather than the full population of faculty. The most rigorous and comprehensive studies tend to produce the lowest estimates of political imbalance.