Debt levels and flows
Debt level is a measure of how much debt is outstanding. Debt flow is a measure of debt level changes over time. Both are basic macroeconomic variables. Debt is used to finance household consumptions, businesses, and government spendings. Within mainstream economics, the levels and flows of public debt (government debt) are seen as a larger cause of concern than those associated with private debt. Measuring debt In measuring debt, stocks and flows are both of interest: stocks are amounts, levels of debt (e.g., $100) and have units of currency (such as US Dollars), while flows are changes in levels – in calculus terms, the derivative – (e.g., $10/year), and have units of currency/time (such as US Dollars/Year). In order to make these stock and flows comparable between countries and across time, one may normalize these by some measure of the size of the country's economy, most often GDP, that is, compute the debt to GDP ratio. For instance, $10 billion in 2000 is a small amount of debt relative to the size of the economy of the United States, but large relative to the size of the economy of Iceland, and dividing by the GDP reflects this. Because GDP is