5.4 Government Deficits and the National Debt
A budget deficit is one year's gap between government spending and tax revenue; the national debt is the accumulated stock of past deficits.
Get the flow-versus-stock distinction down: a budget DEFICIT means spending exceeds tax revenue in a single year (a flow); the national DEBT is the running total of all past deficits minus surpluses (a stock). A shrinking deficit still adds to the debt as long as it stays above zero.
Governments finance deficits by selling bonds — borrowing in the loanable funds market. That borrowing is exactly what drives up the real interest rate and sets up crowding out (Topic 5.5). Running a surplus does the opposite, adding to national saving.
Debt matters through its burdens: interest payments claim a growing slice of future budgets, and servicing debt may require higher future taxes or lower spending. Economists judge sustainability by the debt-to-GDP ratio rather than the dollar amount alone.
Key terms for 5.4
Using 'deficit' and 'debt' interchangeably. The deficit is a one-year FLOW; the debt is the accumulated STOCK — a smaller deficit still grows the debt.
Get AP Econ exam tips in your inbox
Occasional emails with study tips, new interactive graphs, and exam-season reminders. Free — no spam.
No spam. Unsubscribe anytime.