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Policy Evaluation and Research Linkage Initiative (PERLI)

 

The Policy Evaluation and Research Linkage Initiative (PERLI) is a four-year project funded by the National Science Foundation under Grant #2024283 that will end in August 2024. This award established powerful new datasets of linked administrative microdata from California state and local government sources. 

 

Motivation

Social, behavioral, and economic (SBE) research could inform solutions to poverty, income inequality, housing shortages, or other entrenched problems. Government administrative microdata are increasingly vital to SBE research, and have enabled recent breakthroughs in these fields. Yet the potential of these data remains unfulfilled in the United States, where legal and technical barriers have led researchers to rely largely on national survey data (whose reliability has been called into question by several recent papers) and on administrative microdata from other countries, with very different contexts. The lack of accessible, large-scale, linked US administrative microdata limits SBE research, resulting in findings of uncertain accuracy that potentially undermine the very public policy decisions they seek to inform.

Our Project

PERLI expanded the data resources available for quantitative SBE research. Using administrative microdata from California, the world’s 5th largest economy, we created linked longitudinal datasets that unlock new pathways to discovering the causes and consequences of poverty and economic mobility, and whether government interventions help households succeed.

PERLI also refined and disseminated methods of data linkage that do not depend on access to personally identifiable information, thus expanding the universe of data available for research, and providing tools for accessing it in a streamlined fashion while safeguarding privacy. 

The PERLI datasets are available to researchers through a streamlined and secure virtual environment, and accompanied by resources such as data documentation, analysis files, and resources on privacy-preserving linkage methods. 

The PERLI project created three datasets

PERLI has created three datasets:

“Life Course” dataset 
This dataset links anonymized longitudinal data on individuals interacting with a vast array of public services in Sonoma County, California. It captures interactions with criminal justice, health, behavioral health and human services, and housing programs. This dataset facilitates research on complex, cross-domain issues such as poverty, homelessness, and mental illness, and informs more comprehensive policy solutions. Read more and apply here.

“Safety Net” dataset
This dataset links anonymized longitudinal data about individual and household participation in a range of social safety net programs along with wages before, during, and after program participation. These data facilitate research on the efficacy of the existing safety net, successful exits from government support, and shortfalls in eligible take-up. Read more and apply here.

“Household Economics” dataset 
This dataset links anonymized longitudinal household financial information for millions of Americans, including on household income, debt, and credit histories, using the UC Consumer Credit Panel. These data facilitate research on pathways into and out of poverty, the role of debt in weathering and triggering economic shocks, and on household mobility and financial well-being. Read more and apply here.

“Student Supports” dataset
This dataset links student records from the California Student Aid Commission, the California Community College Chancellor’s Office, the California Department of Social Services, and the University of California Consumer Credit Panel. If you are interested in accessing the Student Supports dataset, please contact studentsupports@capolicylab.org for more information. New research project proposals are reviewed on an intermittent basis and final approval is contingent on review from the partner agencies. Any project that uses CDSS data must contribute to improving CDSS program administration.

Resources for Researchers

PERLI has also developed resources to help researchers understand and use these data:

Data documentation — Each dataset is accompanied by relevant and detailed data documentation, developed by CPL in partnership with each data provider. These include descriptions of variables, codebooks, and any known issues of reliability or missingness.

Data linkage methods — As part of PERLI, CPL published a toolkit about data linkage methods. Data linkage is often essential to projects using administrative data, and can greatly influence the results of some studies, but is too rarely discussed by SBE researchers.

For the linkages in this project, we use a privacy-protective record linkage (PPRL) technique that uses one-way encryptions (hashes) to mask identifying information but still allows individual records to be linked across datasets, even when transcription errors lead to small differences in the way that identifiers are recorded. CPL aims to advance the use of this method in SBE research by testing methods and by disseminating resources such as relevant code, linkage metrics, and a white paper for SBE researchers interested in applying this method to their own data. Please read more about this linkage method here.

Accessing the Datasets

The PERLI datasets are hosted on CPL’s Secure Data Hub, a virtual enclave environment designed for secure analysis and research using sensitive administrative microdata. Only approved users have access and only for approved projects. User activities are monitored, logged, and audited. 

We began receiving applications for research projects using the PERLI datasets in 2020. Please check back here as more data becomes available or sign up for our updates list below. Because final approval lies with the contributing data partners, we cannot make guarantees about the likelihood that a proposal will be accepted.

Contact Us

To stay connected about PERLI, please subscribe to our updates list: 

For questions, please visit our FAQ. For other inquiries, please email perli@capolicylab.org.

Contact us

For general inquiries about our research or our services, as well as information on our mailing list, please visit our contact page.

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