Efforts to close the ‘doom loop’ are destined to fail
An egregious example of this problem in the U.S. context is that as the bubble inflated the banking regulators did, and still do, allow the banks to hold unlimited amounts of the debt of Fannie Mae and Freddie Mac, the government-backed mortgage firms, long since failed and in conservatorship. Moreover, the regulators allowed (and indeed promoted, through low risk-based capital requirements) banks to own and finance with deposits the preferred equity of Fannie and Freddie. These were distinctly bad ideas. But what were the poor regulators to do? Their employer, the US government, wanted to expand housing debt and leverage through Fannie and Freddie, and they went along.