Final answer:
An unbalanced budget is not appropriate according to Keynesian economics when the economy is at full employment, as it could lead to inflation without reducing unemployment.
Step-by-step explanation:
According to Keynesian economics, an unbalanced budget is not appropriate when the economy is at full employment. During such a time, any additional government spending can lead to inflationary pressures without reducing unemployment, since the economy is already at its maximum output capacity.
In contrast, unbalanced budgets are considered suitable in scenarios like a recessionary gap, where the economy is below full employment, or when leakages and injections in the economy are out of balance, necessitating fiscal intervention to return to equilibrium.
However, when macro equilibrium is above full employment, which indicates an inflationary gap, Keynes recommends contractionary fiscal policy, such as tax increases or government spending cuts, to prevent inflation rather than running an unbalanced budget.