Why does the United States have a chronic external deficit?

The external deficit is the United States’ main macroeconomic problem: It leads to the rapid accumulation of external debt, posing a threat in the long term to the United States’ solvency and the dollar’s reserve currency role; it makes the country dependent on the countries that finance it; It is the source of political tensions between the United States and China and between the United States and Europe, given the United States’ insistence that the other countries rebalance their trade with it . What accounts for the United States’ chronic external deficit? The dollar is not chronically overvalued in real terms and US exports are not structurally weak; The level of investment is not abnormally high, although the level of savings is low; But fiscal policy is structurally expansionary and the household savings rate is structurally low. We then try to zoom in further: Why does the United States have a chronic fiscal deficit when its social welfare system is small? Primarily because of a permanent desire to reduce the tax burden; What accounts for the low household savings rate? It can be attributed to the high proportion of Americans whose incomes are too low for them to be able to save.