On the website of this Senate office, visitors can search the disclosure reports that individuals who are hired to lobby government officials must file. The website came into being as a result of the Lobbying Disclosure Act of 1995, which aimed to make the business at least somewhat more transparent.

The National Taxpayers Union is a lobbying organization favoring “lower taxes and smaller government.” It favors scrapping the income tax in favor of a “flat tax” or a national sales tax. Since its founding in 1969, the Taxpayers Union has been a critic of what it sees as wasteful federal spending, saying “NTU staffers know a boondoggle when they see it.”

LegiStorm was launched in 2006, originally as a searchable database of congressional staff salaries. It has since expanded to include a range of financial data about legislators and government employees. The site collects staff salaries, trips paid for by private institutions, financial disclosure forms, foreign gifts and earmarks for Congress members and key staff. It also indexes policy reports, congressional schedules, FEC press releases and political news. Much of the data are available elsewhere; for instance, the information on congressional earmarks is drawn from Taxpayers for Common Sense. Some, however, can be difficult to find.

This congressional committee – unlike most – does not have separate Democratic and Republican staffs. It was set up in 1926, when the federal income tax in its present form was only 13 years old. Congress sought professional analysis independent of the Treasury Department, which is run by a political appointee named by the president. The Joint Tax Committee uses a sophisticated, computerized microsimulation model of the U.S. federal income tax system, based on information from a random sample of 200,000 tax returns each year, to project the likely effects of proposed changes in tax law.

Formerly known as the General Accounting Office, the GAO changed its name in July 2004 to the Government Accountability Office. It is the investigative arm of Congress, serving both Republican and Democratic members. The GAO evaluates federal programs, audits federal expenditures, issues legal opinions and makes recommendations for improved efficiency. The head of GAO is known as the comptroller general.

The Congressional Budget Office’s stated mission is to “provide the Congress with the objective, timely, nonpartisan analyses needed for economic and budget decisions.” Its director is appointed jointly by the majority leaders of the House and Senate.

Founded in 1992 by former Sens. Warren Rudman (R., N.H.) and Paul Tsongas (D., Mass.) and former Secretary of Commerce Peter Peterson, the Concord Coalition is “a nationwide, nonpartisan, grassroots organization advocating fiscal responsibility while ensuring Social Security, Medicare, and Medicaid are secure for all generations.”