Estimating bilateral exposures in the German interbank market: Is there a danger of contagion?

Credit risk associated with interbank lending may lead to domino effects, where the failure of one bank results in the failure of other banks not directly affected by the initial shock. Recent work in economic theory shows that this risk of contagion depends on the precise pattern of interbank linkages. We use balance sheet information to estimate a matrix of bilateral credit relationships for the German banking system and test whether the breakdown of a single bank can lead to contagion. We find that in the absence of a safety net, there is considerable scope for contagion that could affect a large proportion of the banking system. The financial safety net (in this case institutional guarantees for saving banks and cooperative banks) considerably reduces—but does not eliminate—the danger of contagion. Even so, the failure of a single bank could lead to the breakdown of up to 15% of the banking system in terms of assets.