Hence, if we increase government debt to pay for the battleship, the deficit as a % of the GDP grows, while if the government levies a new tax to pay for the purchase, it does not. Hence the measure of the deficit as a percentage of the GDP is still valid, since the GDP did not move The balance of trade is the difference between a country's import and export payments and is the largest component of a country's balance of payments. Net exports are the value of a country's total exports minus the value of its total imports, which is used to calculate the GDP in an open economy. US Federal Deficit as Percentage of GDP. Current Surplus or Deficit(-) Percent: -3.00%. Last reported Dec 2017. US Federal Deficit. Source: White House Office of Management and Budget, Summary of Receipts, Outlays, and Surpluses or Deficits (-) as Percentages of GDP.