400 likes | 477 Views
When money matters: liquidity shocks with real effects. John Driffill and Marcus Miller Birkbeck and University of Warwick. Abstract.
E N D
When money matters: liquidity shocks with real effects John Driffill and Marcus Miller Birkbeck and University of Warwick
Abstract • In their ‘workhorse model of money and liquidity’, Kiyotaki and Moore (2008) show how tightening credit constraints can cut current investment and future aggregate supply. • Aggregate demand matches current supply, thanks to a flex-price ‘Pigou effect’ • Switching from a flex-price to a fix-price framework implies that demand failures can emerge after a liquidity shock. • Quantitative estimates by FRBNY using such a framework produce dramatic results: what about the analytics?
Diagram 1. Effect of a stochastic liquidity shock in US that lasts 10 quarters, Del Negro et al. (2009)
Macro Paradigm: Woodford’s Synthesis Interest and Prices (2003) • marked decisive shift in monetary economics from looking at the quantity of money to the cost of borrowing (i.e. from Friedman back to Wicksell • inspired by an over-arching vision: to create a new synthesis reconciling mainline macroeconomics with dynamic General Equilibrium (GE), as practised by RBC theorists in particular.
The Arrow Debreu paradigmat risk? • In the absence of collateral or other credible enforcement , Peter Hammond (1979) argued that, the ‘core’ of the inter-temporal GE model is not sub-game perfect. Further discussion tomorrow? • If this is true for Arrow-Debreu paradigm of GE, it is also true for the DSGE specialisation developed for macroeconomics. Does it matter?
Great Moderation has succumbed to credit crunch • US unemployment rate has doubled from 4.8 per cent to 9.8 percent • “the world is currently undergoing an economic shock every bit as big as the Great Depression shock of 1929-302” Eichengreen and O’Rourke (2009). • “The good news is that the policy response is very different” (zero interest rate, deficit spending, QE) • The bad news is that it lies outside the reach of DSGE • Can Kiyotaki and Moore (2008) model help?
KM(2008) framework • addresses the Hammond critique of DGE: firms cannot borrow at will - with real consequences for composition of output. • heterogeneous investors facing liquidity constraints • want to hold money as a precaution against a lack of finance for investment opportunity • need to add sticky wages/prices for liquidity shocks to have significant real effects; • otherwise the Pigou effect acts as automatic stabiliser!
Kiyotaki and Moore(2008), but with sticky wages/prices as in FRBNY and Driffill/Miller
Fix price macro • If prices are inflexible downward, there will be no Pigou effect to stabilise aggregate demand in the face of a fall of investment • A fall in demand will contract employment if the real wage is determined by bargaining, as argued for the UK in Layard and Nickell, Alan Manning. • Graphical representation follows of how liquidity contraction can cut income conditional on K and q.
Kiyotaki and Moore (2008): “Liquidity, Business Cycles, and Monetary Policy” • Assets involved: • Money and equity • Money is liquid • Equity is not (completely) liquid • only a fraction of holdings can be sold each period • only a fraction of newly produced capital goods can be financed by issuing new equity
Workers – not the focus of attention • Spend what they get • Rational and forward-looking, but impatient and credit constrained. • No borrowing • They can hold money and equity if they choose • Save nothing • Consumption equals wages
Investment Entrepreneurs can only finance investment using money, selling existing equity claims to others, raising equity on new capital, and spending out of current income
Entrepreneurs – play central role, manage production and invest and hold assets • May (prob π) or may not (prob 1-π) have an idea for a profitable investment • Those with no ideas (no investment) • Consume • Save in form of money and equity holdings • Those with an idea (Investors) • Buy new capital goods • Issue equity against them • Use money, other equity holdings, and current income to finance investment
Liquidity constraints – on investment • Entrepreneurs can raise equity against up to a fraction θof new investment. • They can sell off a fraction φt of pre-existing equity (theirs and others) nt • Money is perfectly liquid
Entrepreneur’s budget constraint • Budget: • p – price of money; q – equity price • λ – 1-depreciation rate • n equity held by entrepreneur • Objective - max exp U:
Production • CRS / C-D production function, capital and labour • KM: wage clears labour market • DM: fix money wage and price level – entrepreneurs keep the surplus
Investment and Net Demand Investment demand . Entrepreneurs’ income equals their demand (GM equilibrium)
KM (2008): liquidity driven expansion, ϕincreases, equity more liquid
Saddle Path Dynamics in fix price case: driven by Asset Market and Investment disequilibrium
liquidity shock shifts E to E': with stock market fall leading to recession – or recovery if shock is to be reversed
Figure 6. Numerical Results from DM simulation using FRBNY parameters
Calibration using FRBNY parameters (qtly) • φ = 0.13 (fraction of existing assets an entrepreneur can sell); • discount factor β = 0.99; • fraction of new capital against which an entrepreneur can raise equity, θ = 0.13; • probability of an entrepreneur having an idea for an investment, π = 0.075; • the quarterly survival rate of the capital stock λ = 0.975 • [ our base case steady state: q = 1.12, r = 0.0374, • Mp/K =0.1171, K = 152.5, y =17.26]
Table 2. Impact effects of a 20% cut in ϕ for different lengths of time
Figure 9. Bubble collapse preceding liquidity shock: like 1929
Credit crunch • With firms who want to invest more credit constrained - and workers income constrained - no Pigou effect to stimulate entrepreneurial consumption, a ‘credit crunch’ causes recession. • The antidote discussed by KM should work here too: Quantitative Easing as the government supplies liquidity in exchange for corporate securities.
Conclusion • Switching from a flex-price to a fix-price framework means that demand failures can emerge after a liquidity shock. • AM and RI offer simple analytical treatment of impact and dynamic effects. • Adding bubble might help explain the origin of the shock- it’s when the bubble bursts • Need to add financial intermediaries to get to the heart of the matter
Current UK recession (blue) relative to earlier recessions(brown: 1930s, green and yellow: oil shocks)
Queen Hermione imprisoned for sixteen years: then came reconciliation
Time for a change in Macro? • discredited and discarded in the stagflation that followed the oil price shocks of the 70s and 80s, the Keynesian paradigm of macroeconomic stabilisation has suffered in silence for many years. • but the new DSGE paradigm failed to predict the ‘credit crunch’ - or explain its effects. • Let’s briefly review recent fashions in macro