The US has been spending more than it earns and has to borrow from abroad to fund its real investment.

The excess of inflows over outflows adds to the stock if flows are not instantly perishable.

Treasury bonds are important instruments in regulating the money supply.

Even though members of the European Union have no control over their domestic monetary policies, their undisciplined domestic fiscal policies can still wreak great havoc for the financial health of the Union.

Heavily indebted Greece was taken to task by bond investors who demanded higher yield to offset higher default risk and rating agencies who threatened to downgrade its bonds.

Medicare and Social Security are Ponzi schemes whose long-term financial viability depends on an ever larger body of later contributors paying off a much smaller body of earlier contributors.