About

Robb Willer is a Professor of Sociology at Stanford University (with courtesy appointments in Psychology and the Graduate School of Business). He directs the Politics and Social Change Lab, the AI for Public Benefit Lab, and co-directs the Center on Philanthropy and Civil Society. He studies politics, democracy, social change, and social impacts of artificial intelligence.

Research topics

• Political Science
• Psychology
• Social psychology
• Sociology
• Public relations
• Social Science
• Law
• Medicine
• Psychiatry
• Engineering
• Epistemology
• Demography
• Linguistics
• Clinical psychology
• Neuroscience
• Ecology
• Environmental science
• Philosophy
• Cognitive psychology
• Economics
• Developmental psychology
• Environmental resource management
• Political economy
• Applied psychology

Selected publications

• Huge meta-research project puts claims in social-science papers to the test

  Nature · 2026-04-01

  articleSenior authorCorresponding
  PublisherDOI

• Americans Favor Predistributive Over Redistributive Economic Policies

  SocArXiv (OSF Preprints) · 2026-05-21

  preprintOpen access1st authorCorresponding

  Redistributive policies designed to reduce economic inequality through taxes and transfers (e.g., safety-net benefits funded by progressive taxation) receive less support in the U.S. than in many Western democracies. Recent work suggests Americans may be more receptive to “predistributive” policies, which seek to reduce economic inequality before taxes and transfers (e.g., minimum-wage increases). Yet existing evidence leaves open whether this support gap characterizes contemporary Americans overall, and whether it persists when the same policy proposals are described in predistributive versus redistributive terms, with their core provisions held constant. Across 31 nationally representative U.S. survey waves fielded from 2015 to 2024 (total N=384,248), we find greater support for policies classified as predistributive than redistributive. We then fielded a preregistered experiment with a national U.S. sample (N=1,009), randomly varying whether otherwise identical policy proposals were described as increasing earnings for people lower in the income distribution, shifting resources from higher- to lower-income individuals, or presented only with the brief policy description given in all conditions. Support was higher under predistributive than redistributive descriptions. Comparison with the control condition clarifies this difference: predistributive descriptions received support comparable to control, whereas redistributive descriptions received lower support. Exploratory analyses suggest perceived respect for hard work and deservingness of beneficiaries were associated with the support gap. Together, these results suggest Americans prefer policies that reduce inequality by influencing earnings more than through taxes and transfers.

  Publisher

• Americans Favor Predistributive Over Redistributive Economic Policies

  2026-05-22

  articleOpen accessSenior author

  Redistributive policies designed to reduce economic inequality through taxes and transfers (e.g., safety-net benefits funded by progressive taxation) receive less support in the U.S. than in many Western democracies. Recent work suggests Americans may be more receptive to “predistributive” policies, which seek to reduce economic inequality before taxes and transfers (e.g., minimum-wage increases). Yet existing evidence leaves open whether this support gap characterizes contemporary Americans overall, and whether it persists when the same policy proposals are described in predistributive versus redistributive terms, with their core provisions held constant. Across 31 nationally representative U.S. survey waves fielded from 2015 to 2024 (total N=384,248), we find greater support for policies classified as predistributive than redistributive. We then fielded a preregistered experiment with a national U.S. sample (N=1,009), randomly varying whether otherwise identical policy proposals were described as increasing earnings for people lower in the income distribution, shifting resources from higher- to lower-income individuals, or presented only with the brief policy description given in all conditions. Support was higher under predistributive than redistributive descriptions. Comparison with the control condition clarifies this difference: predistributive descriptions received support comparable to control, whereas redistributive descriptions received lower support. Exploratory analyses suggest perceived respect for hard work and deservingness of beneficiaries were associated with the support gap. Together, these results suggest Americans prefer policies that reduce inequality by influencing earnings more than through taxes and transfers.

  PublisherDOI

• A registered report megastudy on the persuasiveness of the most-cited climate messages

  Nature Climate Change · 2026-01-05 · 3 citations

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Americans Favor Predistributive Over Redistributive Economic Policies

  2026-05-21

  articleOpen accessSenior author

  Redistributive policies designed to reduce economic inequality through taxes and transfers (e.g., safety-net benefits funded by progressive taxation) receive less support in the U.S. than in many Western democracies. Recent work suggests Americans may be more receptive to “predistributive” policies, which seek to reduce economic inequality before taxes and transfers (e.g., minimum-wage increases). Yet existing evidence leaves open whether this support gap characterizes contemporary Americans overall, and whether it persists when the same policy proposals are described in predistributive versus redistributive terms, with their core provisions held constant. Across 31 nationally representative U.S. survey waves fielded from 2015 to 2024 (total N=384,248), we find greater support for policies classified as predistributive than redistributive. We then fielded a preregistered experiment with a national U.S. sample (N=1,009), randomly varying whether otherwise identical policy proposals were described as increasing earnings for people lower in the income distribution, shifting resources from higher- to lower-income individuals, or presented only with the brief policy description given in all conditions. Support was higher under predistributive than redistributive descriptions. Comparison with the control condition clarifies this difference: predistributive descriptions received support comparable to control, whereas redistributive descriptions received lower support. Exploratory analyses suggest perceived respect for hard work and deservingness of beneficiaries were associated with the support gap. Together, these results suggest Americans prefer policies that reduce inequality by influencing earnings more than through taxes and transfers.

  PublisherDOI

• Durably reducing partisan animosity through multiple scalable treatments

  Proceedings of the National Academy of Sciences · 2025-05-09 · 5 citations

  articleOpen accessSenior author

  Recent research has identified several effective strategies for reducing Americans' animosity toward supporters of opposing political parties. However, whether these strategies can durably reduce partisan animosity in a scalable manner and in everyday life remains unclear. We bridge the gap between prior research and useful application by assessing whether exposure to multiple, scalable treatments that portray inparty and outparty members interacting positively, receiving accurate information about one another's views, and learning about cross-party similarities can a) durably shift partisans' sentiments and b) influence partisans' sentiments toward specific, personally known others encountered in everyday life-not only general, hypothetical, or one-off rival partisans. In a longitudinal survey experiment, we find that exposure to three brief, scalable treatments over a week reduces partisan animosity, with effects persisting for at least a month. Moreover, the treatments durably ameliorate animosity toward both general outparty members and a personally known outparty member, specified prior to the treatments. These findings suggest promising avenues for redressing social divisions in real-world contexts.

  PublisherOA PDFDOI

• A Registered Report Megastudy on the Persuasiveness of the Most-Cited Climate Messages

  2025-12-08

  preprintSenior author

  It is important to understand how persuasive the most-cited climate change messaging strategies are. In five replication studies, we found limited evidence of persuasive effects of three highly cited strategies (N=3,216). We then conducted a registered report megastudy (N=13,544) testing the effects of the 10 most-cited climate change messaging strategies on Americans’ pro-environmental attitudes and behavior. Six messages significantly affected multiple preregistered attitudes, with effects ranging from one to four percentage points. Persuasiveness varied little across party lines, inconsistent with theories predicting heterogeneous effects for targeted messages. No message increased pro-environmental donations, suggesting costly behaviors are difficult to influence with messaging alone. Inference of mechanisms driving effects was limited as the most impactful messages influenced multiple mediating variables. Taken together, these results identify several persuasive strategies, while also highlighting the limits of short-form messages for increasing Americans’ support for action to address climate change.

  PublisherDOI

• A Registered Report Megastudy on the Persuasiveness of the Most-Cited Climate Messages

  2025-09-12

  articleSenior author

  It is important to understand how persuasive the most-cited climate change messaging strategies are. In five replication studies, we found limited evidence of persuasive effects of three highly cited strategies (N=3,216). We then conducted a registered report megastudy (N=13,544) testing the effects of the 10 most-cited climate change messaging strategies on Americans’ pro-environmental attitudes and behavior. Six messages significantly affected multiple preregistered attitudes, with effects ranging from one to four percentage points. Persuasiveness varied little across party lines, inconsistent with theories predicting heterogeneous effects for targeted messages. No message increased pro-environmental donations, suggesting costly behaviors are difficult to influence with messaging alone. Inference of mechanisms driving effects was limited as the most impactful messages influenced multiple mediating variables. Taken together, these results identify several persuasive strategies, while also highlighting the limits of short-form messages for increasing Americans’ support for action to address climate change.

  PublisherDOI

• LLM-Generated Messages Can Persuade Humans on Policy Issues

  2025-06-19 · 3 citations

  preprintSenior author

  The emergence of large language models (LLMs) has made it possible for generative artificial intelligence (AI) to tackle many higher-order cognitive tasks, with critical implications for industry, government, and labor markets. Here, we investigate whether existing, openly-available LLMs can be used to create messages capable of influencing humans’ political attitudes. Across three pre-registered experiments (total N = 4,829), participants who read persuasive messages generated by LLMs showed significantly more attitude change across a range of policies - including polarized policies, like an assault weapons ban, a carbon tax, and a paid parental-leave program - relative to control condition participants who read a neutral message. Overall, LLM-generated messages were similarly effective in influencing policy attitudes as messages crafted by lay humans. Participants’ reported perceptions of the authors of the persuasive messages suggest these effects occurred through somewhat distinct causal pathways. While the persuasiveness of LLM-generated messages was associated with perceptions that the author used more facts, evidence, logical reasoning, and a dispassionate voice, the persuasiveness of human-generated messages was associated with perceptions of the author as unique and original. These results demonstrate that recent developments in AI make it possible to create politically persuasive messages quickly, cheaply, and at massive scale.

  PublisherDOI

• Power as a moral magnifier: Moral outrage is amplified when the powerful transgress

  Journal of Experimental Social Psychology · 2025-08-08

  article
  PublisherDOI

Frequent coauthors

• Jan G. Voelkel

  63 shared

• Matthew Feinberg

  34 shared

• J. Kiley Hamlin

  University of British Columbia

  33 shared

• Nicolás Alessandroni

  Concordia University

  33 shared

• Michael C. Frank

  Stanford University

  33 shared

• Krista Byers‐Heinlein

  Concordia University

  33 shared

• Mélanie Söderström

  Stanford University

  33 shared

• Heidi A. Baumgartner

  University of Manitoba

  33 shared

Education

• Ph.D., Sociology

  Stanford University

  2005

• M.A., Sociology

  Stanford University

  2001

• B.A., Sociology

  University of California, Berkeley

  1998

Awards & honors

• Golden Apple Teaching award (2009)