“CBO has estimated the effects of the five-week partial shutdown of the government that started on December 22, 2018, and ended on January 25, 2019. This report presents CBO’s findings, which include the following:

• CBO estimates that the five-week shutdown delayed approximately $18 billion in federal discretionary spending for compensation and purchases of goods and services and suspended some federal services.
• As a result of reduced economic activity, CBO estimates, real (that is, inflation-adjusted) gross domestic product (GDP) in the fourth quarter of 2018 was reduced by $3 billion (in 2019 dollars) in relation to what it would have been otherwise. (Such references are in calendar years or quarters unless this report specifies otherwise.) In the first quarter of 2019, the level of real GDP is estimated to be $8 billion lower than it would have been—an effect reflecting both the five-week partial shutdown and the resumption in economic activity once funding resumed.
• As a share of quarterly real GDP, the level of real GDP in the fourth quarter of 2018 was reduced by 0.1 percent, CBO estimates. And the level of real GDP in the first quarter of 2019 is expected to be reduced by 0.2 percent. (The effect on the annualized quarterly growth rate in those quarters will be larger.)..”