Congressional Budget Office (CBO)

What it does

The Congressional Budget Office is the legislature’s own scorekeeper. Created in 1974 as a counterweight to the executive branch’s estimates, it produces the cost estimates for proposed legislation, the ten-year budget and economic outlook that most public debate references, and long-run projections of the debt, Social Security and Medicare.

Why its numbers are used everywhere

Because they are nonpartisan, methodical and published with their assumptions, CBO projections are the common reference point even for people who disagree with them. When a figure for the deficit ten years out appears in a newspaper, it is usually a CBO number, and when a budget plan claims to cut the deficit, the test is whether the office scores it that way.

What it does not do

It does not recommend policy and it does not forecast in the sense of predicting. Its projections assume current law continues, which is often not what happens, since legislation passed later can move the numbers a long way. The value is in the sensitivity and the reasoning, not in the point estimate.