slide1 n.
Skip this Video
Loading SlideShow in 5 Seconds..
Short run or long run? (full adjustment of capital, expectations, etc.) PowerPoint Presentation
Download Presentation
Short run or long run? (full adjustment of capital, expectations, etc.)

Loading in 2 Seconds...

play fullscreen
1 / 27

Short run or long run? (full adjustment of capital, expectations, etc.) - PowerPoint PPT Presentation

  • Uploaded on

Schools of Macroconomics. Neo-classical growth model. Classical or non-classical? (sticky wages and prices, rational expectations, etc. yes. long- run. Marxist theories? Behavior growth theories? Malthusian trap models?. no. Short run or long run? (full adjustment of capital,

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Short run or long run? (full adjustment of capital, expectations, etc.)' - mihaly

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Schools of Macroconomics





or non-classical?

(sticky wages

and prices, rational

expectations, etc.




Marxist theories?

Behavior growth theories?

Malthusian trap models?


Short run or long run?

(full adjustment of


expectations, etc.)

Real business cycle (RBC);

supply-side economics;

structural models;

misperceptions models





or non-classical?

(sticky wages

and prices, rational

expectations, etc.

Keynesian model

(inflexible w and p,

Suboptimal behavior,

PC, IS-MP, etc.)


review is curve expenditures
REVIEW: IS curve (expenditures)

Basic idea: describes equilibrium in goods market.

Finds Y where planned I = planned S or planned expenditure = planned output.

Basic set of equations:

  • Y = C + I + G
  • C = a + b(Y-T)
  • T = T0 + τ Y [note assume income tax, τ = marginal tax rate]
  • I = I0 – dr [note i = r because zero inflation]
  • G = G0
review mp curve with the dual mandate
REVIEW: MP curve with the dual mandate

The Taylor Rule

Begin with a monetary policy equation in the form of a “Taylor rule”:

(TR) i = π + r* + b(π-π*) + cy

r* is the equilibrium real interest rate, π inflation rate, π* is inflation target, y is log output gap [log(Y/Yp)], b and c are parameters.

mp curve with inflation
MP curve with inflation

Now add inflation to the MP curve.

Assume that inflation is a function of output (this will be covered later):

(PC)π= π*+φ y + η (η=inflation shock)

(TR) i = π + r* + b(π-π*) + cy

So new MP curve is:

i = π + r* + b(φ y + η) + cy


(MP) i = π + r* + (bφ+c) y + bη

(MP’) i = π + r* + λy [λ = bφ+c for η = 0].

So adding inflation makes the MP curve steeper, but does not change the basic structure..

algebra of is mp analysis
Algebra of IS-MP Analysis
  • The analysis looks at simultaneous equilibrium in goods market and financial markets (Main St and Wall St).
  • The algebraic solution for equilibrium Ye is:

Ye = μ*A0 –μ* d r*

where μ* = μ/(1 +λμd) = multiplier with monetary policy.

μ= simple multiplier > μ* ; A0 = autonomous spending

= a - bT0 + G0 + I0 + demand shocks,

Note impacts on output:

Positive: G, I0, NX, demand shocks

Negative: risk premium, inflation shocks


IS-MP diagram

r = real

interest rate

MP(r*, inflation shocks)



IS(G, T0, demand

shocks …)


Y = real output (GDP)

monetary v fiscal policy
Monetary v. fiscal policy

Monetary policy: Actions by central bank that affect interest rates and asset prices by balance sheet operations and regulations.

  • Open market operations, asset purchases, reserve requirements. Do not directly affect incomes.

Fiscal policy: Actions by governments that affect incomes and output directly through purchases and taxes.

  • Government purchases (military, teachers, roads,…)
  • Taxes (income taxes, corporation taxes, …)
  • Transfers or negative taxes (social security benefits, UI, …)
important historical examples
Important historical examples

Monetary policy:

Fed raised discount rate in Great Depression to defend gold reserves, and deepened Depression.

Fed engaged in forward guidance and asset purchases in Great Recession to stimulate output.

Fiscal policy:

Huge US military spending in 1941-45 brought economy out of recession.

Kennedy-Johnson tax cuts of 1963 were first explicitly Keynesian stimulus policy.

Reagan “supply side” tax cuts of 1981 were designed to increase potential output growth.

Obama stimulus package in 2009 spurred growth but became highly controversial.

1. What are the effects of fiscal policy?
  • Consider a fiscal policyholding monetary policy constant.
  • In normal times, because MP curve slopes upward, expenditure multiplier is reduced due to crowding out.
is shock as in fiscal expansion
IS shock (as in fiscal expansion)





Y = real output (GDP)


Multiplier Estimates by the CBO

Congressional Budget Office, Estimated Impact of the ARRA, April 2010

inflationary shock and stagflation
Inflationary shockand stagflation

MP(ηt > 0)

MP(ηt = 0)





Y = real output

dual v single mandate
Dual v single mandate

What are MP curves with different mandates?

(Dual: Fed)i= π + r* + b(π-π*) + cy

(Single: ECB) i= π + r* + b(π-π*)

(MP: Fed) i = π + r* + (bφ+c) y + bη

(MP: ECB) i = π + r* + (bφ) y + bη

So the MP curve of Fed is steeper. This means:

  • Fed tolerates greater volatility of inflation, but stabilizes unemployment.
  • ECB tolerates more unemployment but very averse to inflation
ecb single mandate
ECB Single Mandate

In accordance with Article 127(1) and Article 282(2) of the Treaty on the Functioning of the European Union, the primary objective of the ESCB shall be to maintain price stability

While the Treaty clearly establishes the primary objective of the ECB, it does not give a precise definition of what is meant by price stability. The ECB’s Governing Council has announced a quantitative definition of price stability:

"Price stability is defined as a year-on-year increase in the Harmonised Index of Consumer Prices (HICP) for the euro area of below 2%."

dual v single mandate1


Dual v single mandate







Y = real output (GDP)

japan short term interest rates 1994 2012
Japan short-term interest rates, 1994-2012

Liquidity trap from 1996 to today:

16 years and counting.


US in current recession

Policy has hit the “zero lower bound” five years ago.

conventional monetary expansion in liquidity trap
Conventional monetary expansion in liquidity trap

i= nominal

interest rate





Y = real output (GDP)

fiscal policy in liquidity trap
Fiscal policy in liquidity trap

r = real

interest rate





Y = real output (GDP)


Can you see why macroeconomists emphasize the importance of fiscal policy in the current environment?

“Our policy approach started with a major commitment to fiscal stimulus. Economists in recent years have become skeptical about discretionary fiscal policy and have regarded monetary policy as a better tool for short-term stabilization. Our judgment, however, was that in a liquidity trap-type scenario of zero interest rates, a dysfunctional financial system, and expectations of protracted contraction, the results of monetary policy were highly uncertain whereas fiscal policy was likely to be potent.”

Lawrence Summers, July 19, 2009


Older approach emphasize the supply of money (Mankiw’s IS analysis).

Extreme version is “monetarism,” which holds that demand for money does not depend on interest rate.

  • Very influential in 1960s through 1983 or so.

- When tried, led to very poor predictions

Very important tradition, particularly Friedman and Schwartz, A Monetary History of the United States.

Deemphasized in Econ 122, but still important in many other views of macro (warning about dissensus)

summary on is mp model
Summary on IS-MP Model

This is the workhorse model for analyzing short-run impacts of monetary and fiscal policy

Key assumptions:

- Inflexible prices

- Unemployed resources

Now on to analysis of

- Panics

- Great Depression in IS-MP framework.