CRS Reports: Congressional Research Service Major research arm for Congress. They provide policy, legislative, and legal analysis to congress regardless of party affiliation. Exceptional analysis, very authoritative, and non-biased.
GAO Reports: Government Accountability Office Known as the "congressional watchdog". Investigates the effectiveness of government programs to identify policy problems and needed changes.
CBO Reports: Congressional Budget Office Provides Congress with biannual forecasts of the economy and how much government programs will cost. Analyze public policies especially with respect to money issues.
From Harvard Kennedy School of Government library. Searches hundreds of U.S. and international think tanks.
Think Tanks are units within a university, foundation, advocacy group, government, or non-government organization that research public policy issues and publish their findings to inform or influence policy. They are a key player in policy formation.
Tip: Use Think Tank Search to search across many reports at once. If one seems particularly relevant, go to that think tank's home page and mine it for more publications.