Policy makers need information about the nation—ranging from trends in the overalleconomy down to the use by individuals of Medicare—in order to evaluate existingprograms and to develop new ones.

This information often comes from researchbased on data about individual people, households, and businesses and other organizations,collected by statistical agencies.

The benefit of increasing data accessibility to researchers and analysts is betterinformed public policy. To realize this benefit, a variety of modes for data access—including restricted access to confidential data and unrestricted access to appropriatelyaltered public-use data—must be used.

The risk of expanded access to potentiallysensitive data is the increased probability of breaching the confidentiality of thedata and, in turn, eroding public confidence in the data collection enterprise.

Indeed, the statistical system of the United States ultimately depends on the willingnessof the public to provide the information on which research data are based.Expanding Access to Research Data issues guidance on how to more fully exploitthese tradeoffs. The panel''s recommendations focus on needs highlighted by legal,social, and technological changes that have occurred during the last decade.