Unlike Gertrude Stein's roses, it's not the case that a transistor is a transistor.

OSLO With Jeremy Stein s return to his academic post at Harvard at the end of May, the US Federal Reserve Board lost its leading proponent of the view that monetary policy should be used to lean against financial excesses.

And a striking new voice has joined the fray Kara Stein, a commissioner at the Securities and Exchange Commission (SEC). Stein delivered a far reaching speech in June, in which she argued that systemic risk must become a more central responsibility for financial market regulators.

Jeremy Stein (no relation to Kara Stein), until recently a governor of the US Federal Reserve System, has suggested that forced fire sales of assets are one important way that risks are transmitted. When asset prices fall as a result of such selling, the solvency of other firms can be affected even if the creditworthiness of the underlying asset has not really changed.

And it is difficult to deny that the Fed should take a close interest in the funding strategies of foreign banks operating in the US. Another Fed governor, Jeremy Stein, has pointed out that foreign banks have dollar liabilities of roughly 8 trillion, much of it short term wholesale funding.

For better or worse, the fact that the most severe political and social turbulence is yet to come at least means that Europe will be unable to afford the dithering and half measures that produced Japan s lost decade. If something cannot go on forever, as the economist Herbert Stein famously put it, it will stop.