When the capital development of a country becomes a by-product of the activities of a casino, the job is likely to be ill-done, JM Keynes, General Theory of Employment, Interest and Money Ch 12, p142 in Google Book edition, Atlantic Publishers
If there is one economic doctrine that has been central to thinking about economic and social policy over the last three decades, it is the Efficient Markets Hypothesis, or more properly, the efficient financial markets hypothesis. The EMH says that financial markets are the best possible guide to the value of economic assets and therefore to decisions about investment and production.
Although economists since Adam Smith have pointed out the virtues of markets in general, the EMH with its focus on financial markets is specific to the era of finance-driven capitalism that emerged from the breakdown of the Keynesian Bretton Woods system in the 1970s. The EMH justified, and indeed demanded, financial deregulation, the removal of controls on international capital flows and the massive expansion of the financial sector that ultimately produced the greatest financial crisis in history.