Bank Liquidity, Interbank Markets, and Monetary Policy

A major lesson of the recent financial crisis is that the interbank lending market is crucial for banks facing large uncertainty regarding their liquidity needs. This paper studies the efficiency of the interbank lending market in allocating funds. We consider two different types of liquidity shocks leading to di¤erent implications for optimal policy by the central bank. We show that, when confronted with a distribu- tional liquidity-shock crisis that causes a large disparity in the liquidity held among banks, the central bank should lower the interbank rate. This view implies that the traditional tenet prescribing the separation between prudential regulation and mon- etary policy should be abandoned. In addition, we show that, during an aggregate liquidity crisis, central banks should manage the aggregate volume of liquidity. Two di¤erent instruments, interest rates and liquidity injection, are therefore required to cope with the two di¤erent types of liquidity shocks. Finally, we show that failure to cut interest rates during a crisis erodes financial stability by increasing the risk of bank runs.bank liquidity;interbank markets;central bank policy;financial fragility;bank runs

Interbank comptetition with costly screening

We analyse credit market equilibrium when banks screen loan applicants. When banks have a convex cost function of screening, a pure strategy equilibrium exists where banks optimally set interest rates at the same level as their competitors. This result complements Broecker’s (1990) analysis, where he demonstrates that no pure strategy equilibrium exists when banks have zero screening costs. In our set up we show that interest rate on loans are largely independent of marginal costs, a feature consistent with the extant empirical evidence. In equilibrium, banks make positive profits in our model in spite of the threat of entry by inactive banks. Moreover, an increase in the number of active banks increases credit risk and so does not improve credit market effciency: this point has important regulatory implications. Finally, we extend our analysis to the case where banks have differing screening abilities.Interbank Competition, Screening, Credit Risk, Adverse Selection

Regulating Financial Conglomerates

We analyse a model of financial intermediation in which intermediaries are subject to moral hazard and they do not invest socially optimally, because they ignore the systemic costs of failure and, in the case of banks, because they fail to account for risks which are assumed by the deposit insurance fund. Capital adequacy requirements are designed to minimise the social costs of these effects. We show that banks should always have higher regulatory capital requirements than insurance companies. Contrary to received wisdom, when banks and insurance companies combine to form financial conglomerates we show that it is socially optimal to separate their balance sheets. Moreover, the practice of "regulatory arbitrage", or of transfering assets from one balance sheet to another, is welfare increasing.

Full vs Partial Market Coverage with Minimum Quality Standards

The consequences of the adoption of quality standards on the extent of market coverage is investigated by modelling a game between regulator and low-quality firm in a vertically differentiated duopoly. The game has a unique equilibrium in the most part of the parameter range. There exists a non-negligible range where the game has no equilibrium in pure strategies. This result questions the feasibility of MQS regulation when firms endogenously determine market coverage

Clearing algorithms and network centrality

I show that the solution of a standard clearing model commonly used in contagion analyses for financial systems can be expressed as a specific form of a generalized Katz centrality measure under conditions that correspond to a system-wide shock. This result provides a formal explanation for earlier empirical results which showed that Katz-type centrality measures are closely related to contagiousness. It also allows assessing the assumptions that one is making when using such centrality measures as systemic risk indicators. I conclude that these assumptions should be considered too strong and that, from a theoretical perspective, clearing models should be given preference over centrality measures in systemic risk analyses

Nearly optimal solutions for the Chow Parameters Problem and low-weight approximation of halfspaces

The \emph{Chow parameters} of a Boolean function $f: \{-1,1\}^n \to \{-1,1\}$ are its $n+1$ degree-0 and degree-1 Fourier coefficients. It has been known since 1961 (Chow, Tannenbaum) that the (exact values of the) Chow parameters of any linear threshold function $f$ uniquely specify $f$ within the space of all Boolean functions, but until recently (O'Donnell and Servedio) nothing was known about efficient algorithms for \emph{reconstructing} $f$ (exactly or approximately) from exact or approximate values of its Chow parameters. We refer to this reconstruction problem as the \emph{Chow Parameters Problem.} Our main result is a new algorithm for the Chow Parameters Problem which, given (sufficiently accurate approximations to) the Chow parameters of any linear threshold function $f$, runs in time \tilde{O}(n^2)\cdot (1/\eps)^{O(\log^2(1/\eps))} and with high probability outputs a representation of an LTF $f'$ that is \eps-close to $f$. The only previous algorithm (O'Donnell and Servedio) had running time \poly(n) \cdot 2^{2^{\tilde{O}(1/\eps^2)}}. As a byproduct of our approach, we show that for any linear threshold function $f$ over $\{-1,1\}^n$, there is a linear threshold function $f'$ which is \eps-close to $f$ and has all weights that are integers at most \sqrt{n} \cdot (1/\eps)^{O(\log^2(1/\eps))}. This significantly improves the best previous result of Diakonikolas and Servedio which gave a \poly(n) \cdot 2^{\tilde{O}(1/\eps^{2/3})} weight bound, and is close to the known lower bound of $\max\{\sqrt{n},$ (1/\eps)^{\Omega(\log \log (1/\eps))}\} (Goldberg, Servedio). Our techniques also yield improved algorithms for related problems in learning theory

Regulating financial conglomerates

We investigate the optimal regulation of financial conglomerates which combine a bank and a non-bank financial institution. The conglomerate’s risk-taking incentives depend upon the level of market discipline it faces, which in turn is determined by the conglomerate’s liability structure. We examine optimal capital requirements for stand-alone institutions, for integrated financial conglomerates, and for financial conglomerates that are structured as holding companies. For a given risk profile, integrated conglomerates have a lower probability of failure than either their stand-alone or decentralized equivalent. However, when risk profiles are endogenously selected, conglomeration may extend the reach of the deposit insurance safety net and hence provide incentives for increased risk-taking. As a result, integrated conglomerates may optimally attract higher capital requirements. In contrast, decentralised conglomerates are able to hold assets in the socially most efficient place. Their optimal capital requirements encourage this. Hence, the practice of “regulatory arbitrage”, or of transferring assets from one balance sheet to another, is welfare-increasing. We discuss the policy implications of our finding in the context not only of the present debate on the regulation of financial conglomerates but also in the light of existing US bank holding company regulation

Do bad borrowers hurt good borrowers? A model of biased banking competition

This paper explores a two-bank model in which, first, one bank correctly estimates the probability of low-quality loan repayment while the other overestimates it, and second, both banks have identical convex costs when granting loans. In this context of optimistically biased banking competition, we show how the unbiased bank follows the biased competitor as long as the bias of the latter is not too large. This would favour bad borrowers, who get better credit conditions at the expense of good borrowers. As a consequence, the presence of a biased bank increases welfare as long as the expected default rate is sufficiently high. Contrariwise, in subprime markets, biased banking competition would be socially harmful.info:eu-repo/semantics/publishedVersio