Long-Run Consequences of Stabilization Policies

Before going further, a quick recap of the toolkit from Units 3–4 — because this unit is about what happens after these tools are used.

• Fiscal policy: government spending (G) and taxes (T) — expansionary (more G / less T) to fight recessions, contractionary (less G / more T) to fight inflation.
• Monetary policy: in a limited-reserves system, the reserve requirement, the discount rate, and open market operations; in an ample-reserves system, administered rates (the discount rate as a ceiling, Interest on Reserves as a floor) targeting the federal funds rate.
• Both sets of tools work in the short run by shifting Aggregate Demand. The rest of this unit asks: what happens over the longer run — especially if these tools are used repeatedly, or relied on too heavily?

• The Short-Run Phillips Curve (SRPC) shows an inverse relationship between the inflation rate and the unemployment rate: lower unemployment tends to come with higher inflation, and vice versa.
• This is really just the AD-AS model viewed from a different angle: an increase in AD moves the economy along the SRPC toward lower unemployment/higher inflation; a decrease in AD moves it the other way, toward higher unemployment/lower inflation.
• The Long-Run Phillips Curve (LRPC) is vertical at the natural rate of unemployment — in the long run, there is no permanent tradeoff between inflation and unemployment; the economy always tends back to the natural rate, regardless of the inflation rate.
• What shifts the SRPC: changes in inflationary expectations, or supply shocks (the same shocks that shift SRAS in the AD-AS model).
• Stagflation appears as a rightward shift of the SRPC itself (not a movement along it) — at any given inflation rate, unemployment is now higher than before. This is caused by an adverse supply shock (like a sudden spike in oil prices), which raises the price level while lowering output at the same time.

Why the short-run tradeoff disappears in the long run — adaptive expectations

Start at point A, where wages and prices are set expecting, say, 2% inflation. If AD then rises, prices rise faster than the wages that were locked in around that 2% expectation, so profits rise and businesses expand output, moving to point B (lower unemployment, higher actual inflation than expected). But this is temporary: workers and resource suppliers eventually notice the higher actual inflation and demand higher wages/prices to match, raising costs and pushing businesses to cut output back — moving to point C, back at the natural rate of unemployment, but now at the higher, fully-expected inflation rate. Any inflation rate can end up consistent with the natural rate once expectations catch up — which is exactly why the LRPC is vertical.

• The Equation of Exchange: MV = PY, where M = money supply, V = velocity of money (how many times the average dollar is spent on final goods/services per year), P = price level, and Y = real output (real GDP). Note that PY is just nominal GDP, so if nominal GDP is already given, you may not need P and Y separately.
• Strict monetarists believe velocity (V) is stable and predictable, so changes in output, prices, or nominal GDP mainly come from changes in the money supply (M).
• Quantity Theory of Money: at full employment (Y fixed at potential) with stable V, growing the money supply faster than real output leads directly to inflation — sustained inflation is, in this view, "a monetary phenomenon." A useful shortcut for growth-rate questions: money supply growth rate ≈ inflation rate + real GDP growth rate.
• This is why strict monetarists are skeptical of discretionary monetary policy: they argue the money supply should simply grow at the same rate as real GDP, since growing it faster just causes inflation without any lasting increase in real output — a concept called long-run monetary neutrality (in the long run, changes in the money supply affect only nominal variables like the price level, not real GDP, real interest rates, or real wages).

• A budget deficit is a flow variable — the shortfall between government revenue and spending in a single year.
• The national debt is a stock variable — the accumulated total of all past deficits, minus any surpluses.
• The government (the Treasury) finances a deficit by selling bonds — borrowing from savers and lenders, which adds directly to the national debt.

• Crowding out occurs when government borrowing (to finance a deficit) raises interest rates enough to reduce private investment and interest-sensitive spending.

The mechanism, two equivalent ways to see it

• Bond market: the Treasury sells more bonds to borrow, increasing the supply of bonds. More bonds supplied lowers the equilibrium bond price — and since bond prices and yields move inversely, this means interest rates rise.
• Loanable funds market: government borrowing increases the demand for loanable funds. With supply unchanged, the equilibrium real interest rate rises, and higher borrowing costs crowd out some private investment.

• International connection: higher domestic interest rates attract foreign investors seeking better returns, increasing demand for the domestic currency — the currency appreciates, making exports relatively more expensive and imports cheaper, which reduces net exports (a further drag working against the original policy goal).
• Implication: crowding out means that expansionary fiscal policy can partly undercut its own goal — rising interest rates offset some of the intended boost to AD — and can also work against expansionary monetary policy operating at the same time.

• Economic growth means a sustained increase in real GDP per capita over time — not a short-run fluctuation or simply putting previously idle resources back to work. Graphically, it's an outward shift of the PPC or a rightward shift of LRAS.

Sources of growth

• Physical capital — more/better capital per worker means more output per worker.
• Human capital — both the quantity of labor (encouraged by things like a higher labor force participation rate) and its quality (education, training, health).
• Technology — getting more output from the same inputs.

• Saving and investment are linked: higher national saving frees up more loanable funds for business investment, and that investment expands both AD in the short run and AS/LRAS in the long run — this is why policies that encourage saving (like tax incentives) can support long-run growth.

Supply-side policy ideas aimed at boosting long-run growth include: reducing business regulation, reducing income and business taxes, encouraging saving (through tax incentives), investing in education, investing in research/technology, reducing barriers to trade, reducing disincentives to work, and reducing national debt (freeing up loanable funds that would otherwise compete with private borrowers).

One related, debated idea is the Laffer Curve — the theoretical claim that beyond some point, higher tax rates can reduce total tax revenue by discouraging economic activity, implying certain tax cuts could partly (or, in strong versions of the claim, fully) "pay for themselves." This remains a genuinely contested point among economists — critics argue the revenue-recovering effect is usually much smaller than proponents claim, especially at the tax rates most economies actually operate at.