AS/AD Framework Flashcards
Policy Rule:
Rt - r̅ = m̅(πt - π̅)
Why is the policy rule considered “closed loop”
Rt →Ỹ → π → Rt - 1 endogenous variable is determined by another
AD Curve:
Ỹt = a̅ - b̅m̅(πt - π̅)
How does the AD curve function?
If the central bank sees an inflation rate higher than its target π̅, the monetary policy rule dictates an increase in interest rates. The higher interest rates cause a reduction in I and a slowdown in economic activity - a movement along the AD curve
What does m̅ describe?
willingness of the central bank to incite a recession/boom to combat inflation - the steepness of AD - high m̅ = flat (more ΔỸ), low m̅ = steep
What is compared in the AD/AS diagram?
π vs Ỹ NOT Δπ
What can shift the AD curve?
a̅ - temporary, π̅ - permanent
AS Curve:
πt = πte + v̅Ỹt + o̅t
What is the Stabilisation Problem associated with the AS/AD framework?
In the IS-MP model, it is possible to adjust R to keep Ỹ at potential, so there is no reason to go through the cycle.
The problem arises because the monetary policy rule responds only to inflation and not to changes in output.
The length of time it takes to ascertain whether a shock is a boom or a bust further complicates policy
Policy Rule + Fisher equation =
it = r̅ + πt + m̅(πt - π̅)
What is the Taylor Rule?
Taylor rule describes on average how central banks conduct MP. Has morphed from descriptive to prescriptive
Taylor Rule Parameters:
m̅ = 1/2 r̅ = 2% π̅ = 2%
How long ahead do central banks forecast inflation and why?
Central bank tries to forecasts inflation 1-2 years in the future because of the MP lag
What is Rational Expectations?
People use all information at their disposal to make their best forecast of the coming rate of inflation. people do not make systematic errors, they take all available information - people look to the long run
R.E. + credible CB + o̅ =
If firms know that the CB will fight aggressively to keep inflation at a low rate no matter the consequences, then they are much less likely to raise prices sharply in response to an inflation shock.
What can affect short run output under R.E.?
It is only surprises that can affect Ỹ - i.e. + o̅
What is the Policy Ineffectiveness Proposition?
The government is unable to incite any output changes under R.E. as following any increase in G (AS curve shift) or tax changes as AD will shift immediately so short run output remains at potential
What conditions are necessary for the Policy Ineffectiveness Proposition?
R.E. & fluid prices
How can Central Banks control inflationary expectations?
Announce an explicit monetary policy rule or adopt an explicit target inflation rate for the medium horizon
An explicit inflation target make it easier for the central bank to stabilise output?
Possibly, when the central bank eases monetary policy to stimulate the economy, if firms and workers understand the commitment to the target inflation rate, they won’t be tempted to deviate from their standard price setting behaviour and this will allow the monetary stimulus to exert its desired short term effect of output
What does R.E. incentivise the Central Bank to do?
Under R.E. There is in principle an incentive for governments to control expectations in a way such that they can surprise the public - the only policy that matters (affects output) is the policy that isn’t anticipated
What does coordination of inflationary expectations require?
Credibility and transparency on the part of the central bank
What is constrained discretion?
The idea that a central bank has the flexibility to respond to shocks in the short run, but remain committed to a particular target inflation rate in the long run
What is the Real Business Cycle?
Assumes R.E. - i.e. AD can’t affect Ỹ substantially
Assumes the classical dichotomy in both long and short run
Everything including cycles is determined by the real side
Cycle is caused by factors that affect Y̅
- Fluctuations are driven by real forces
- Savings rate, Investment rate, TFP, - productivity changes
Against stabilisation policies