Sacramento, CA, September 18, 2025 — Sending light-touch “nudges” such as emails and robocalls increased the number of low-income Californians who claimed the expanded Child Tax Credit and stimulus payments during the pandemic. That’s according to new research published this month in the Proceedings of the National Academy of Sciences.
Researchers from UC Berkeley, Harvard University, and Code for America teamed up with the California Dept. of Social Services (CDSS) to test the power of “nudges” for getting low-income people to claim these credits and payments. In a series of four experiments, CDSS sent emails, text messages, or calls to over 500,000 Californians, alerting them of their eligibility and giving them instructions on how to claim the credits and payments.
Some people received a “light touch” version of the nudges such as an email or a robocall, while others received a “higher touch” version, which directed recipients to a tax-filing assistance hotline or led to them receiving a call from staff from that hotline. The researchers also tested if varying the message framing would have an impact on take-up — such as using language about the benefits “belonging” to the recipient, or messaging telling recipients that the claiming process had been simplified.
Recorded voice messages, emails, and text messages all had significant and positive impacts on people filing as compared to people who did not receive outreach. The light-touch outreach consistently increased take-up of the benefits by .14 to 2 percentage points, but higher touch, proactive outreach, varying messaging, and more precisely targeting the messages yielded “minimal additional benefits.”
The outreach resulted in millions of dollars disbursed to low-income Californians. Light-touch outreach, in particular, was highly cost-effective: for every $1 spent on outreach, $50 – $8,000 in benefits were claimed/disbursed. Another way to measure it is the cost of each additional tax return being submitted (to claim the credit or payment). This ranged from a cost of $0.15 (for emails) to $26 for recorded voice messages for each additional tax return being submitted. However, for the higher-touch nudges, the costs to staff a tax-filing assistance hotline (ranging from $200,000 to over $2 million) meant that costs ranged from $142 per additional return filed, all the way up to $1,062 for people who received proactive calls.
“Because the credits and stimulus payments were distributed using our tax system, we knew some low-income Californians were at risk of missing out, so we wanted to see what types of nudges could get people to claim these valuable credits,” explains co-author Jesse Rothstein, a professor of economics and public policy at UC Berkeley and faculty director of the California Policy Lab’s UC Berkeley site. “These results can help inform state policymakers who will be grappling with budget cuts in the recent federal bill — our results show there’s a very strong return on investment from well-designed efforts to help families get money that they are eligible for.”
“Our findings show that light-touch interventions can be an incredibly cost-effective lever to increase take-up of safety-net programs,” adds co-author Dr. Jessica Lasky-Fink, research director at the People Lab. “However, they also underscore the need for more research to help identify the most effective and efficient ways to reach out to people who are at risk of missing out on their benefits.”
“Governments around the country are using “nudges” like these to help increase the number of people enrolling in safety-net programs,” explains co-author Elizabeth Linos, a professor of public policy and management at the Harvard Kennedy School of Government, and faculty director of the People Lab. “We’re grateful to our partners at CDSS for working with us to see what works and what’s cost-effective in terms of closing take-up gaps.”
The study is available at PNAS’ website: https://www.pnas.org/doi/10.1073/pnas.2504747122
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The California Policy Lab generates research insights for government impact. Through hands-on partnerships with government agencies, CPL performs rigorous research across issue silos and builds the data infrastructure necessary to improve programs and policies that millions of Californians rely on every day.
The People Lab aims to empower the public sector by producing cutting edge research on the people of government and the communities they serve. Using evidence from public management and insights from behavioral science, we study, design, and test strategies for solving urgent public sector challenges in three core areas: strengthening the government workforce; improving resident–government interactions; and reimagining evidence-based policy-making.