Bubbles, Banks, and Financial Stability

This paper asks two main questions: (1) What makes some asset price bubbles more costly for the real economy than others? and (2) When do costly bubbles occur? We construct a model of rational bubbles under credit frictions and show that when bubbles held by banks burst this is followed by a costly financial crisis. In contrast, bubbles held by ordinary savers have relatively muted effects. Banks tend to invest in bubbles when financial liberalisation decreases their profitability.

Is Private Leverage Excessive?

I examine whether a benevolent government can improve on the free market allocation by setting capital requirements for private borrowers in a stochastic model with collateral constraints. Previous theoretical studies have found that when asset prices enter into bor- rowing constraints, pecuniary externalities between atomistic agents can make the laissez faire equilibrium constrained ine¢ cient. For reasonable parameter values, I find that, quan- titatively, the answer is 'no', private and government leverage choices coincide. Limiting private leverage by imposing capital requirements has the beneficial e¤ect of dampening the effects of the collateral amplification mechanism. This reduces fire sales in recessions and limits the negative externality that individual asset sales have on other credit constrained borrowers. However, we find that capital requirements are a blunt tool. They tax the activities of highly productive entrepreneurs and reduce the amount they produce in equilibrium. This reduces total factor productivity and steady state consumption. In the end, society faces a choice between high but unstable consumption in the free borrowing world and low but stable consumption in the regulated world. The government chooses the former.Collateral constraints, Capital Requirements

Winners and Losers in Housing Markets

This paper is a quantitatively-oriented theoretical study into the interaction between housing prices, aggregate production, and household behaviour over a lifetime. We develop a life-cycle model of a production economy in which land and capital are used to build residential and commercial structures. We find that, in an economy where the share of land in the value of structures is large, housing prices react more to an exogenous change in expected productivity or the world interest rate, causing large redistribution effects between net buyers and net sellers of houses. Changing the financing constraint, however, has limited effects on housing prices.Real estates, Land, Housing Prices, Life cycle, Collateral constraints.

Winners and Losers in House Markets

This paper is a quantitatively-oriented theoretical study of the interaction between housing prices, aggregate production, and household behavior over a lifetime. We develop a life-cycle model of a production economy in which land and capital are used to build residential and commercial real estates. We find that, in an economy where the share of land in the value of real estates is large, housing prices react more to an exogenous change in expected productivity or the world interest rate, causing a large redistribution between net buyers and net sellers of houses. Changing financing constraints, however, has limited effects on housing prices.Real estates, land, housing prices, life cycle, collateral constraints

Self-confirming Inflation Persistence

In this paper we simulate a central bank subject to the misperception that prices are indexed to past inflation in periods when firms are unable to re-optimise. It thinks, in other words, that inflation is intrinsically persistent. The central bank sets monetary policy optimally subject to this belief. The central bank updates its beliefs about in¬dexation using a constant gain learning scheme. The data generated by such policy lead to beliefs about inflation persistence being effectively self-confirming in a wide variety of setttings. These results offer a tentative answer to why it appears that inflation is persistent at some times and in some countries, and at others not. The answer is that policymakers sometimes believe inflation to be persistent, and sometimes do not.

Financial frictions and the monetary transmission mechanism: theory, evidence and policy implications

This paper provides a brief survey of the role of financial frictions in the monetary transmission mechanism. After noting some of the key stylised facts that any model of the transmission mechanisms must be consistent with, we discuss both the classical interest rate channel and the credit and bank lending channels of monetary transmission. We then review the empirical evidence relating to the relative importance of these channels. Finally we consider what impact the presence of significant financial frictions might have on the conduct of monetary policy JEL Classification: E52, E58, E44bank-lending channel, credit channel, monetary policy, transmission mechanism

Bubbles, Banks, and Financial Stability

This paper asks two main questions: (1) What makes some asset price bubbles more costly for the real economy than others? and (2)When do costly bubbles occur? We construct a model of rational bubbles under credit frictions and show that when bubbles held by banks burst this is followed by a costly financial crisis. In contrast, bubbles held by ordinary savers have relatively muted effects. Banks tend to invest in bubbles when financial liberalisation decreases their profitability.Rational bubbles, Financial Frictions, Financial Stability

A model of borrower reputation as intangible collateral

In this paper, we build a framework which can generate endogenous fluctuations in downpayment requirements. We extend the model of Kiyotaki and Moore (1997) by considering an environment, in which savers can keep their anonymity but borrowers cannot. This allows lenders to punish defaulting borrowers by excluding them from future borrowing. They cannot however stop them from saving in the anonymous financial market. We show how the possibility of such market exclusion can lead to the emergence of intangible collateral in equilibrium alongside the tangible collateral which is usually studied in the literature. Fluctuations in the value of intangible collateral are isomorphic to fluctuations in the amount of borrowing firms can secure against the value of their tangible assets. We find that, when we combine the intangible collateral mechanism in our paper with counter-cyclical variance of idiosyncratic productivity shocks, this helps to generate realistic negative co-movement of downpayment requirements and aggregate output over the business cycle. In this case, the presence of intangible collateral increases the amplification of business cycle fluctuations relative to the standard Kiyotaki-Moore (1997) model

Is Private Leverage Excessive?

I examine whether a benevolent government can improve on the free market allocation by setting capital requirements for private borrowers in a stochastic model with collateral constraints. Previous theoretical studies have found that when asset prices enter into bor- rowing constraints, pecuniary externalities between atomistic agents can make the laissez faire equilibrium constrained ine¢ cient. For reasonable parameter values, I find that, quan- titatively, the answer is 'no', private and government leverage choices coincide. Limiting private leverage by imposing capital requirements has the beneficial e¤ect of dampening the effects of the collateral amplification mechanism. This reduces fire sales in recessions and limits the negative externality that individual asset sales have on other credit constrained borrowers. However, we find that capital requirements are a blunt tool. They tax the activities of highly productive entrepreneurs and reduce the amount they produce in equilibrium. This reduces total factor productivity and steady state consumption. In the end, society faces a choice between high but unstable consumption in the free borrowing world and low but stable consumption in the regulated world. The government chooses the former

Is Private Leverage Excessive?

I examine whether a benevolent government can improve on the free market allocation by setting capital requirements for private borrowers in a stochastic model with collateral constraints. Previous theoretical studies have found that when asset prices enter into bor- rowing constraints, pecuniary externalities between atomistic agents can make the laissez faire equilibrium constrained ine¢ cient. For reasonable parameter values, I find that, quan- titatively, the answer is 'no', private and government leverage choices coincide. Limiting private leverage by imposing capital requirements has the beneficial e¤ect of dampening the effects of the collateral amplification mechanism. This reduces fire sales in recessions and limits the negative externality that individual asset sales have on other credit constrained borrowers. However, we find that capital requirements are a blunt tool. They tax the activities of highly productive entrepreneurs and reduce the amount they produce in equilibrium. This reduces total factor productivity and steady state consumption. In the end, society faces a choice between high but unstable consumption in the free borrowing world and low but stable consumption in the regulated world. The government chooses the former