Better measurement of risk-taking is important not just to regulators, but also to banks and their investors, according to the Bank of England's Andy Haldane, who said today that "risk illusion rather than a productivity miracle" is what drove the financial sector's high returns in the run up to the crisis.

Speaking at The Future of Finance conference at the London School of Economics and Political Science this morning, the Bank's executive director of financial stability stressed the importance, and difficulty, of weighing finance's contribution to the wider economy when evaluating potential post-crisis reforms.