Will the asset quality review and stress tests conducted by the European Central Bank and the European Banking Authority mark a turning point in the eurozone’s crisis? Up to a point. They are an improvement on what has gone before. But they are not a complete fix for the banking sector, still less for the economy’s wider problems.

GD EXCISEDThe optimistic assessment is that the ECB has at least done enough to mend the banking system. There are two things to be said for this judgment: first, the ECB has taken a close look at the quality of assets in the system; and, second, the “stresses” imposed in the tests are tough. They seem comparable to those imposed by the Federal Reserve on US banks. The ECB concluded that 25 institutions, nine of them Italian, would need to add a total of €25bn in capital. This number has already fallen to €13bn because of capital-raising undertaken this year.

Perhaps the most important possibility omitted by this assessment is that of sovereign default. This bears on a fundamental concern: risk-weighted capital requirements, on which the analysis is based, involve making judgments about the safety of different types of assets. This is especially problematic in the eurozone, where the lack of a unified fiscal backstop for banks means that national governments are responsible for rescuing troubled institutions. Moreover, the solvency of the eurozone’s highly indebted members is more doubtful than that of countries with their own currencies. Since a banking crisis would be even harder to deal with in the eurozone than elsewhere, it would be wise for its banks to have bigger capital buffers that stand a better chance of preventing one. This is particularly important when actual leverage is so much higher than the risk-weighted capital ratios suggest. (See chart.)