Thus, exactly because finance is efficient at responding to changing profit opportunities, it can become harmful for the rest ef the economy. And this is why James Tobin, the 1981 Nobel laureate in economics, talked of the need to 'throw some sand in the wheels of our excessively efficient international money markets'. For this purpose, Tobin proposed a financial transaction tax, deliberately intended so slow down financial flows. A taboo in polite circles until recently, the so-called Tobin Tax has recently been advocated by Gordon Brown, the former British prime minister. But the Tobin Tax is not the only way in which we can reduce the speed gap between finance and the real economy. Other means include making hostile takeovers difficult (hereby reducing the gains from speculative investment in stocks), banning short-selling (the practice of selling shares that you do not own today), increasing margin requirements (that is, the proportion of the money that has to be paid upfront when buying shares) or putting restrictions on cross-border capital movements, especially for developing countries.

A taboo in polite circles until recenty, the so-called Tobin Tax has recently been advocated by Gordon Brown