What does the following statement below mean?
'Certainly economies cannot continue indefinitely with ever-rising debt loads. But in recessionary times, successful expansionary policy may actually lower long-term debt through generating employment and higher tax revenues. As Paul Krugman points out: "Suppose that government uses borrowed money to buy useful things like infrastructure. The true social cost will be very low, because the spending will put resources that would otherwise be unemployed to work [and allow private debtors to pay down their debt] … the argument that debt can’t cure debt is just wrong."'