Goetz von Peter

Interbank tiering and money center banks

This paper provides evidence that interbank markets are tiered rather than flat, in the sense that most banks do not lend to each other directly but through money center banks acting as intermediaries. We capture the concept of tiering by developing a core-periphery model, and devise a procedure for tting the model to real-world networks. Using Bundesbank data on bilateral interbank exposures among 1800 banks, we find strong evidence of tiering in the German banking system. Econometrically, bank-specific features, such as balance sheet size, predict how banks position themselves in the interbank market. This link provides a promising avenue for understanding the formation of financial networks.

Filling in the Blanks: Network Structure and Interbank Contagion

The network pattern of financial linkages is important in many areas of banking and finance. Yet bilateral linkages are often unobserved, and maximum entropy serves as the leading method for estimating counterparty exposures. This paper proposes an efficient alternative that combines information-theoretic arguments with economic incentives to produce more realistic interbank networks that preserve important characteristics of the original interbank market. The method loads the most probable links with the largest exposures consistent with the total lending and borrowing of each bank, yielding networks with minimum density. When used in a stress-testing context, the minimum-density solution overestimates contagion, whereas maximum entropy underestimates it. Using the two benchmarks side by side defines a useful range that bounds the cost of contagion in the true interbank network when counterparty exposures are unknown.

Debt-Deflation: Concepts and a Stylised Model

This paper proposes a model of how agents adjust their asset holdings in response to losses in general equilibrium. By emphasising the relation between deflation and financial distress, we capture some original features of the early debt-deflation literature, such as distress selling, instability, and endogenous monetary contraction. The agents affected by a shock sell off assets to prevent their debt from crowding out consumption. But their distress-selling causes a decline in equilibrium prices, and the resulting losses elicit reactions by all agents. This activates several channels of debt-deflation. Yet we show that this process remains stable, even in the presence of large shocks, high indebtedness, and wide-spread default. What keeps the asset market stable is the presence of agents without prior debt or losses, who borrow to exploit the expected asset price recovery. By contrast, debt-deflation becomes unstable when agents try to contain their indebtedness, or when a credit crunch interferes with the accommodation necessary for stability.