Congressional Budget Office (CBO)
This agency was created by Congress in 1974. Its "mission is
to provide the Congress with objective, timely, nonpartisan analyses
needed for economic and budget decisions and with the information
and estimates required for the Congressional budget process." It is
best known for its estimates of federal spending, revenue, and the
resulting deficit, but it also generates numerous reports, studies,
papers, and memorandums (the different names reflect different
levels of review and how the document was requested). Every new one
is available here, as well as Congressional testimony and cost
estimates, and they cover the complete range of federal spending and
taxing (both at the aggregate level and down to specific programs).
Besides these reports, they offer considerable data. Their "Current
Budget Projections" is their well-known twice-annual budget
projections, which contain many details besides the basic federal
revenues, expenses, and deficit. "Current Economic Projections"
offer both short-range (18-24 month) and long-range macro forecasts
(the latter do not include cyclical fluctuations). Their "Historical
Budget Data" contains extensive information on not just budgetary
data, but actual and potential GDP and the NAIRU (the
"non-accelerating inflation rate of unemployment," or the rate of
unemployment consistent with stable inflation). "Current Status of
Discretionary Appropriations" details this category of spending.
Finally, their "Monthly Budget Review" summarizes federal spending,
revenue, and the deficit month-by-month.