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Information economics and macroeconomic theory


Information economics and macroeconomic theory Roger B. Myerson Max Weber Lecture European University Institute, 18 June 2014 – PowerPoint PPT presentation

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Title: Information economics and macroeconomic theory

  • Information economics and macroeconomic theory
  • Roger B. Myerson
  • Max Weber Lecture
  • European University Institute, 18 June 2014
  • "A model of moral-hazard credit cycles" Journal
    of Political Economy 120(5)847-878 (2012).
  • "Rethinking the principles of bank regulation a
    review of Admati and Hellwig's 'Banker's New
    Clothes'" Journal of Economic Literature
    52197-210 (2014).
  • Note on Keynes and the theory of banking
  • http//
  • These notes
  • http//

  • Macroeconomists have learned much since 1929, and
    the world is significantly better for it.
  • But the financial crisis of 2008 and its
    aftermath have shown that economists still need
    to learn more.
  • I will explain why I think that we should look to
    information economics, particularly to
    moral-hazard agency theory, for much of the new
    understanding that is needed.
  • Foundations of macroeconomic theory by Keynes,
    Fisher, and Friedman
  • long preceded the foundations of information
    economics in 1970s,
  • which depended on game theory by von Neumann and
  • There has been some work to construct
    macroeconomic models with agency theory, since
    Bernanke-Gertler (1989), but more is needed.

A General Theory without bank failures or credit
  • Much of macroeconomic theory follows from or
    responds to Keynes's General Theory of
    Employment, Interest and Money (1936).
  • But the General Theory discusses of saving and
    investment at length without seriously
    considering financial intermediation or bank
  • His General Theory even ignores his own
    observations on how monetary policy can affect
    aggregate investment without changing interest
  • "There is normally a fringe of unsatisfied
    borrowers to whom a bank would be quite ready to
    lend if it were to find itself in a position to
    lend more.
  • The existence of this unsatisfied fringe allows
    the Banking System a means of influencing the
    rate of investment supplementary to the mere
    changes in the short-term rate of interest."
    Keynes, Treatise on Money, 1930.
  • Why did he omit this vital observation from his
    "General Theory"?
  • Such credit rationing may have seemed
    theoretically indefensible in 1936...

Credit rationing from moral hazard
  • Credit rationing may have seemed theoretically
    indefensible in 1936, but 35 years later,
    Stiglitz and Weiss (1981) derived it from moral
    hazard and adverse selection in finance.
  • When an entrepreneur borrows from a bank to
    finance a new venture, the probability of its
    success may depend on entrepreneurial efforts
    that a bank cannot directly monitor.
  • To motivate such hidden efforts, the borrower
    must anticipate substantial profit from his
    venture's success (moral-hazard rents).
  • This need to let borrowers keep enough profit
    from their success can impose an upper bound on
    the interest rate that banks can charge.
  • So interest rates might not rise even when
    qualified eager borrowers cannot find funds.

The vital role of information economics
  • Problems of getting people to choose hidden
    actions appropriately are called moral hazard.
  • Problems of getting people to share hidden
    information honestly are called adverse
  • Such problems of agents having different
    information are analyzed by modern information
    economics, which first developed in 1970s,
    building on advances in game theory.
  • Banks and other financial intermediaries earn
    profits by having better information about
    investments than their depositors, so a theory of
    banking depends on information economics.
  • "Twenty years ago, there was no microeconomic
    theory of banking, for the simple reason that the
    general equilibrium model was unable to explain
    the role of banks. Since then, a new
    asymmetric-information paradigm has emerged that
    has been useful in explaining the role of banks
    and pointing out weaknesses of the banking
  • X. Freixas, J.-C. Rochet (1997)

Adverse selection can make expert investors
issue debt
  • Entrepreneurs and industrialists have expertise
    about the potential profitability of their firm
    and its investment opportunities.
  • When an investment opportunity requires outside
    financing, they may choose between issuing debt
    or new equity shares.
  • Selling new equity can dilute the value of their
    own shares.
  • Given any market price at which they can sell new
    equity shares, they are more likely to do so when
    their private information suggests that this
    price may be too high.
  • Thus, outside investors see a firm's decision to
    issue new equity as bad news about the value of
    the firm (winner's curse).
  • This inference decreases the price that outside
    investors are willing to pay for equity shares.
  • Thus, entrepreneurs often find it better to issue
    debt, the value of which is less uncertain to
    investors. (Myers Majluf, 1984).
  • ...Short-term debt avoids risks of future adverse
    news about firm.

Deflation can cripple the economy's key experts
  • ...Financial and industrial leaders with best
    information about investment opportunities tend
    to finance investments largely by monetary debt.
  • When prices are lower than was expected, however,
    these debts become harder to repay from the
    profits of real economic investments.
  • Deflation causes a general decrease in the real
    net worth of those who know the most about
    investment opportunities in the economy.
  • When such entrepreneurs are overburdened by debt,
    they are less able to make new productive
    investments, which can cause a recession.
  • Then an inflation could help reduce the real
    burden of entrepreneurs' debts.
  • So the vital role of price-level changes in
    Fisher's (1933) debt-deflation theory of
    depressions can be derived from adverse selection
    in finance.
  • The wealth of entrepreneurs and other informed
    financial agents becomes a key macro state
    variable in a balance-sheet theory of recessions
    and monetary policy.

Probing the foundations of balance-sheet
recession theory
  • The net wealth of informed financial agents
    becomes a key macro state variable in a
    balance-sheet theory of recessions and monetary
  • When all informed agents are poorer, investment
    opportunities are lost, underemployment then can
    increase marginal returns to investment.
  • If the possibility of such an event were
    anticipated, the agents would prefer to have
    their real debt burden reduced in such an event,
    as could be achieved by inflationary monetary
    policy in a balance-sheet recession.
  • The real impact of monetary policy here depends
    on informed agents' financing their investments
    with debt that is in monetary units.
  • DiTella (2013) Why don't firms borrow in a broad
    economic index?
  • Their choice to do so might be seen as evidence
    that they got information suggesting that the
    index is likely to fall. (Winners' curse again.)
  • Adverse inference can make choice of debt
    numeraire a game of multiple equilibria, with a
    focal equilibrium in money issued by the

Focusing on moral hazard in financial
  • Moral hazard in financial intermediation has an
    essential fundamental role at the heart of any
    capitalist economy.
  • Problems of moral hazard in banking were evident
    at many stages of the recent financial crisis.
  • A successful economy requires industrial
    concentrations of capital that are vastly larger
    than any typical individual's wealth.
  • The mass of small investors must rely on
    specialists to do the work of identifying good
    investment opportunities.
  • Individuals who hold such financial power may be
    tempted to abuse it for their own personal
  • Bankers and other financial intermediaries borrow
    much of what they invest, but their incentives to
    invest well depend on their having a stake in the
    profits of their investments (capital).

Can moral hazard in banking cause recessions?
  • In "Moral-hazard credit cycles," I show how
    macroeconomic fluctuations can be driven by moral
    hazard in financial intermediation.
  • I assume investors can find good investments only
    through financial agents, who may be tempted to
    divert funds to their cronies' bad investments.
  • Such behavior is efficiently deterred by
    promising big late-career rewards for agents who
    consistently deliver successful investments.
  • The promise of one big bonus at the end can
    motivate good behavior throughout an agent's
  • This need to invest through agents who have
    long-term career incentive plans can create
    complex macroeconomic dynamics.
  • When there is a shortage of trusted financial
    agents, investment is reduced, and employment may
  • But recruiting more young agents then can create
    a future surplus, as their responsibilities will
    grow until retirement under efficient incentive
  • So recovery is gradual and yields subsequent
    booms and recessions.

  • Moral hazard credit cycles the formal model
  • A financial agent who is new at t can serve n
    periods (t,...,tn?1), retires at tn.
  • An investment of size h at time t will return, at
    time t1, ?t1h if success, else 0, with
    P(succ)? if supervised appropriately, else
    P(succ)? if wrongly, where ? gt ?.
  • Acting wrongly yields hidden benefits worth ?h to
    agent at time t.
  • Risk-neutral agents discount future payoffs at
    rate ? per period.
  • (Assuming ? lt (1??/?)2 implies wrongful action
    is not worthwhile in equilibrium.)
  • With agent's expected rewards v from success or w
    from failure at time t1, need
  • ?v (1??)w/(1?) ? ?h ?v (1??)w/(1?)
    (incentive constraint),
  • v?0, w?0 (limited liability).
  • To invest h at t, the agent's minimal expected
    reward (moral-hazard rent) at t1 is
  • ?v(1??)w hM, with v hM/? and w0, where
    M ?(1?)?/(???).
  • Investors supply funds elastically at rate ?, and
    expect no surplus in equilibrium.
  • Optimal contracts new agent at t will get
    M(1?)n?1/?n at tn if always succeeds, will
    invest (1?)s/?s at ts if always succeeds until
    then, else 0.
  • If new agents invest Jt at each t, total
    investment at t is It ?s?0,1,...,n?1
  • Assume expected surplus at t1 depends on
    investment by ??t1? (1?) R(It), where R(.)
    is a decreasing investment-demand function.
  • Equilibrium condition for new agents to be hired
    at t R(It)...R(Itn?1) M.

  • Investment amounts handled by different cohorts
    of bankers with 10-period careers, starting at
    time 1 with bankers investing only 80 of
    steady-state amounts.
  • Parameters n10, ?0.1, ?0.95, ?0.57,
    ?0.12, R(I) 0.36 ? 0.327 I. (M 0.33)

Financial regulation who monitors the monitor?
  • Adverse selection creates impetus for debt
    financing, but moral hazard implies that those
    who control a firm must have some stake in its
    profits (capital).
  • Banks monitor entrepreneurs' capital when they
  • To maintain depositors' trust, someone must
    monitor banks' capital.
  • America 1907 JP Morgan as monitor of last resort
    ...and monopolizer?
  • Public regulators and central banks as monitors
    of last resort.
  • Regulatory capital requirements that are based on
    public information can help reduce the
    adverse-selection problem in selling new equity.
  • Central bank's lending can signal confidence in
    value of a bank's assets.
  • Basel tried to encourage safe investments by
    requiring less capital for them, but capital
    provides the owners' basic incentive to limit
  • Such rules created systemic risk when assets were
    wrongly judged safe (mortgage-backed securities,
    sovereign government debt).
  • Public officials are also subject to moral hazard
    temptations, and their democratic accountability
    is an essential part of the system.
  • Regulations which cannot be publicly monitored
    may not be credible.

Shocks of moral hazard parameters
  • Moral-hazard agency theory can offer a new view
    of macroeconomic fluctuations driven by changes
    in moral hazard parameters.
  • In model of moral-hazard credit cycles, suppose a
    shock could change moral-hazard parameters (such
    as ?, the fraction an agent can take).
  • Legal and political reforms or new control
    systems may allow small investors to invest with
    less moral-hazard rents for intermediaries.
  • The ability to attract global investment with
    less agency cost can be a vital key to economic
  • But controls for new securities might prove less
    effective than believed.
  • What if investors overestimated their deterrents
    against malfeasance?
  • Agents whose temptations are greater than their
    promised rewards would quietly cheat investors,
    until the pattern becomes evident.
  • Then a sudden loss of trust in financial agents
    could severely reduce investment, until financial
    agents could accumulate more capital.

Conclusion incorporating finance into
  • Paul Krugman's view of what economists have to
  • "First, they have to face up to the inconvenient
    reality that financial markets fall far short of
    perfection, that they are subject to
    extraordinary delusions and madness of crowds.
  • Second, they have to admit that Keynesian
    economics remains the best framework we have for
    making sense of recessions and depressions.
  • Third, they'll have to do their best to
    incorporate the realities of finance into
  • Paul Krugman, NYTimes, 6 Sept 2009
  • I agree strongly with Krugman's third point, that
    economists need to incorporate finance into
    macroeconomic theory.
  • But we are unlikely to do this by using an old
    Keynesian theory that was developed when
    economists had no analytical models of banking or
    financial markets.

Conclusion applying information economics in
  • In Keynes' day, differences among traders'
    information were "market imperfections," but now
    economists regularly analyze problems of trust
    among people with different information.
  • This is the subject of information economics and
    agency theory, and it is essential for
    understanding financial problems today.
  • In particular, when information is costly,
    members of a crowd may rationally choose to rely
    on the expertise of others, whose temptation to
    mislead must be countered by greater long-run
    rewards from maintaining a good reputation.
  • A collapse in the supply of such good reputations
    would indeed be a crisis.

  • "A model of moral-hazard credit cycles" Journal
    of Political Economy 120(5)847-878 (2012).
  • "Moral-hazard credit cycles with risk-averse
    agents" to appear in J. of Economic Theory
    (2014). http//
  • "On Keynes and the theory of banking" (2010 blog)
  • http//
  • "Rethinking the principles of bank regulation a
    review of Admati and Hellwig's 'Banker's New
    Clothes'" Journal of Economic Literature
    52197-210 (2014).
  • These notes
  • http//