Castells is currently the data manager and an impact analyst for the Head Start CARES study, a national evaluation of three evidence-based strategies to improve the social and emotional development of children in Head Start. She is responsible for managing the data acquisition, processing and analysis of the project’s multiple data sources, contributing to the research design and analysis plans, and coauthoring the impact report. She is also working on the Rent Reform Demonstration, a study designed to test an alternative rent policy that supports work for Section 8 voucher recipients, where she is contributing to the research design and leading random assignment. Previously, she was the data manager and analyst for the Next Generation project, which examined how welfare and employment policies affect low-income children, where she was involved in designing and conducting analyses and coauthoring papers. She also worked on the Evaluation of Child Care Subsidy Strategies, a test of alternate child care subsidy policies, where she led the processing of the project’s survey data, processed and analyzed administrative data, conducted impact analyses, and coauthored a final report. Prior to MDRC, Castells was a case manager at a nonprofit housing agency. She has a BA from Middlebury College and an MA in public policy from Johns Hopkins University.