 Critical to the Austrian examination of the operation of the competitive market process is the primacy placed on property rights, relative prices, and profit-and-loss accounting. The emphasis on institutional infrastructure informed Austrian perspectives on price theory and the market system, on monetary and capital theory, and on obstacles to socialist economic planning in particular and to interventionism more generally. To Hayek, the idea of prices without property is a grand illusion, and efforts to control economic activity through prohibitions and regulations are plagued by unintended consequences and unforeseen costs.