Microdata from government agencies is believed to be valuable for economics research, and yet access to this data is highly restricted due to concerns about privacy and security. We provide an empirical assessment of the use and impact of restricted-access data that researchers can analyze at the U.S. Census Bureau’s secure facilities. Our findings show that the use of Census Bureau’s confidential data is growing and the publications employing it have a higher impact on the scientific and policy debate. However, adoption remains largely limited to established researchers from prestigious institutions. Our results and discussion inform the design of policies that balance privacy protection with accessibility to confidential microdata.