Violations of the uncovered interest-rate parity – a zero-profit equilibrium condition in foreign-exchange markets – seems to consistently give rise to profitable currency trading. This column highlights the risky nature of this phenomenon, arguing that it is the exposure to stock-market cash flows that is the key secret to making money from global currency portfolio investments. High returns from currency trading compensate investors for taking on severe stock-market risks.

Macroprudential policy is meant to reduce the risks from the financial sector spilling over to the wider economy. But the debate over how to do so goes on. This column argues that macroprudential policy can be analysed through the prism of market failures that it is supposed to address.

In the wake of the 2008 financial crisis, there has been burgeoning interest in macroprudential policy as an overarching framework to address the stability of the financial system as a whole rather than only its individual components. This column, based on a new dataset from 49 countries, shows that some macroprudential instruments are effective in reducing procyclicality in the financial system, and thus systemic risks.

The effective regulation of banks requires identification of systemically important financial institutions. This column discusses a method to estimate the capital that a financial firm would need to raise if we have another financial crisis. This measure of capital shortfall is based on publicly available information but is conceptually similar to the stress tests conducted by US and European regulators.

The financial sector has become increasingly complex in terms of its speed and interconnectedness. This column says that market discipline won’t stabilise financial markets, and complexity makes regulating markets more difficult. It advocates substantial intervention in order to restructure the banking industry, address institutional complexity, and correct misaligned incentives.

Over the last three decades the US financial sector has grown six times faster than nominal GDP. This column argues that there comes a point when the financial sector has a negative effect on growth – that is, when credit to the private sector exceeds 110% of GDP. It shows that, of the advanced countries currently suffering in the fallout of the global crisis were all above this threshold.

The problem of banks being too big to fail haunts discussions of regulation. This column provides new evidence on the implicit support provided to banks deemed too-difficult-to-fail and too-difficult-to-unwind in Europe and the US. It finds that regulators could be doing a much better job.

Today's big banks are enormous. By 2008, 12 banks worldwide had liabilities exceeding $1 trillion. This column, using data on banks from 80 countries over the years 1991-2009, provides new evidence on how large banks differ in terms of their risk and return outcomes and investigates how market perceptions of bank risk are affected by bank size. It concludes that policies should reward bank managers for keeping their banks safe rather than for making them big.

How to regulate systemic risk? This column presents a new CEPR discussion paper assessing the performance of Pigouvian taxes and quantity-based regulations in containing the social costs of high-risk banking. It finds that, depending on how banks differ, the socially efficient solution may be attained with Pigouvian taxes, quantity regulations, or a combination of both.

Just how much systemic risk remains in the advanced economies? This column uses Markov-switching techniques to examine volatility in equity, interbank, sovereign credit-default swaps, and foreign-exchange markets. It finds that while overall systemic stress emanating from interbank spreads and foreign-exchange volatility has subsided, there are still pockets of systemic risk, particularly in sovereign credit default swaps and equity markets – and this is especially the case for Europe’s periphery.