1. LECTURE 8: DYNAMIC INCONSISTENCY OF MONETARY POLICY, AND HOW TO ADDRESS IT
Question: Why is inflation π > 0 more often than π < 0?
Why is π sometimes very high?
One of several answers: Declarations of low-inflation monetary policy by central banks are “dynamically inconsistent.”
Next question: What institutions can address dynamic inconsistency?
API-120 Prof. J.Frankel

2. Dynamic inconsistency: The intuition
Assume governments, if operating under discretion, choose monetary policy and hence AD so as to maximize a social function of Y & π.
=> Economy is at tangency of AS curve & one of the social function’s indifference curves.
Assume also that the social function centers on 𝑌 > 𝑌 , even though this point is unattainable, at least in the long run.
Assume W & P setters have rational expectations.
=> πe (& AS) shifts up if rationally-expected E π shifts up.
=> πe = E π = π on average.
economy is at point B on average. Inflationary bias: πe = E π > 0.
Lesson: The authorities can’t raise Y anyway, so they might as well concentrate on price stability at point C.
API-120 Prof. J.Frankel

3. ● • ● ● π πe 𝑌 then to get the higher Y
3. But πe adjusts upward in response to observed π>0.
The LR or Rational Expectations equilibrium must feature πe = π.
Result: inflationary bias π>0, despite failure to raise Y above 𝑌 .
2. If πe would stay at 0, π ●
then to get the higher Y
it would be worth paying the price of π>0. πe ●
4. The country would be better off
“tying the hands”
of the central bank.
Result: π=0. And yet Y = 𝑌 (no worse than average under discretion). ● •
Barro-Gordon innovation: It is useful to think of society’s 1st choice as Y= 𝑌
(& π=0), even if it is unattainable. 𝑌 𝑌 𝑌
API-120 Prof. J.Frankel

4. Time-Inconsistency of Non-Inflationary Monetary Policy
(Romer 11.53)
  + Policy-maker minimizes quadratic loss function:
where the target
=>
(11.54)
API-120 Prof. J.Frankel

5. Given discretion, the CB chooses the monetary policy and inflation rate where:.
Take the mathematical expectation:
+ Rational expectations:
, the inflationary bias.
=>
(11.58)
API-120 Prof. J.Frankel

6. Addressing the dynamic consistency problem
How can the CB credibly commit to a low-inflation monetary policy?
Announcing a target π = 0 is time-inconsistent, because a CB with discretion will inflate ex post, and everyone knows this ex ante.
CB can eliminate inflationary bias only by establishing non-inflationary credibility,
which requires abandoning the option of discretion,
so public will see the CB can’t inflate even if it wants to.
CB “ties its hands,” as Odysseus did in the Greek myth.
API-120 Prof. J.Frankel

7. Addressing the Time-Inconsistency Problem (continued)
Reputation
Delegation. Rogoff (1985): Appoint a CB with high weight on low inflation a ′ >> a , and grant it independence. It will expand at only π = 𝝈 𝒂′ ( 𝒚 − 𝒚 ) << inflationary bias of discretion.
Binding rules. Commit to rule for a nominal anchor:
1. Price of gold 4. Nominal GDP 2. Money growth 5. CPI 3. Exchange rate
API-120 Prof. J.Frankel

8. Addressing the Time-Inconsistency Problem (continued)
Reputations. With multiple periods, a CB can act tougher in early periods, to build a reputation for monetary discipline.
Backus-Driffill (1985) model: people are uncertain if the CB is of hard-money or soft-money “type.”
Then even a soft CB may act tougher, to influence subsequent expectations.
API-120 Prof. J.Frankel

9. Delegation
Alesina & Summers: Central banks that are institutionally independent
of their governments have lower inflation rates on average.
API-120 Prof. J.Frankel

10. for transition economies
“Central Bank Independence, Inflation and Growth in Transition Economies,” P.Loungani & N.Sheets, IFDPS95-519  (1995)
API-120 Prof. J.Frankel

11. Limitations to the argument for central bank independence
Some consider it undemocratic.
The argument only works if the right central bankers are chosen.
Although independence measures are inversely correlated with inflation, these measures have been debated and,
more importantly, the choice to grant independence could be the result of priority on reducing inflation.
As with rules to address time-inconsistency, there is at best weak empirical evidence that it succeeds in reducing inflation without loss of output.
As with rules, one loses ability to respond to SR shocks.
Post-2008-GFC, the goal in advanced countries has been to get π up, not down.
API-120 Prof. J.Frankel

12. Inflation Targeting (IT)
Many developing countries adopt IT:
Five advanced countries adopt IT:
Agénor & Pereira da Silva, 2013, Fig "Rethinking Inflation Targeting: A Perspective from the Developing World," CGBCR DP 185, U.Manchester. .

13. Countries adopting IT experienced lower inflation Gonçalves & Salles, 2008, “Inflation Targeting in Emerging Economies…” JDE
API-120 Prof. J.Frankel

14. Appendix 1: Introducing disturbances into the Barro-Gordon model à la Rogoff (1985) and Fischer (1987)
AD shocks
No effect on average inflation: Eπ = σ 𝑎 ( 𝑦 - 𝑦 ).
Discretionary monetary policy could usefully offset AD shocks, so they don’t show up as fluctuations in  & y, if lags in monetary policy are shorter than lags in adjustment of W & P.
=> Choice of rules vs. discretion then becomes choice of eliminating LR inflation bias (E=0) vs. SR shocks.
API-120 Prof. J.Frankel

15. Appendix 2: Global inflation began long-term decline after 1990. Why?
Better understanding of costs of inflation and the temporariness of the AS tradeoff ?
Spread of commitment devices such as central bank independence, hard exchange rate pegs (currency boards & monetary unions), & IT?
Rogoff (2003): Globalization & increased competition have reduced  and/or and thereby the inflationary bias
API-120 Prof. J.Frankel

16. peak: early 80s
API-120 Prof. J.Frankel

17. Continued from previous
peak: ≈ 1990
peak: early 90s
API-120 Prof. J.Frankel

18. Most remaining advanced countries had granted independence to their central banks by 2003.
From Ed Balls,  James Howat, and Anna Stansbury,, “After the financial crisis 1: The case for central bank independence,” March 2016, HKS ,p.26; based on the CBI measure of V. Grilli, D. Masciandaro, & G. Tabellini, 1991, “Political and monetary institutions and public financial policies in the industrial countries,” Economic Policy, pp ; using 2003 data from M.Arnone, B.Laurens, and J. Segalotto. "Measures of central bank autonomy: empirical evidence for OECD, developing, and emerging market economies." IMF Working Papers (2006): 1-38.

19. Many EM/developing countries had also granted Central Bank Independence by 2003
From Ed Balls,  James Howat, and Anna Stansbury, “After the financial crisis 1: The case for central bank independence,” March 2016, HKS, p.26; based on the CBI measure of V. Grilli, D. Masciandaro & G.Tabellini, 1991, “Political and monetary institutions and public financial policies in the industrial countries,” Economic Policy, pp ; using 2003 data from M.Arnone, B.Laurens and J.Segalotto. "Measures of central bank autonomy: empirical evidence for OECD, developing, and emerging market economies." IMF Working Papers (2006): 1-38.

20. Appendix 3: Comparison of alternate rules (M1 vs. E vs. CPI …)
The choice of anchor depends on:
Credibility of the commitment
Tradeoff: advantage of time-consistent commitment vs. ability to stabilize short-term shocks
Must compare E(Loss) function for M vs. GDP vs. ex.rate vs. P targets)
Original treatment due to Rogoff (1985)
Other objectives served (e.g., a peg reduces exchange rate risk)
API-120 Prof. J.Frankel

21. 6 proposed nominal targets and the Achilles heel of each:
API-120 Prof. J.Frankel

22. END OF LECTURE 8: DYNAMIC INCONSISTENCY OF MONETARY POLICY, AND HOW TO ADDRESS IT
API-120 Prof. J.Frankel