socialist economic planners lack all of the knowledge required to make optimal decisions. Those who agree with this criticism view it as a refutation of socialism, showing that socialism is not a viable or sustainable form of economic organization. The debate rose to prominence in the 1920s and 1930s and that specific period of the debate has come to be known by historians of economic thought as the socialist calculation debate. Mises argued in a 1920 essay "Economic Calculation in the Socialist Commonwealth" that the pricing systems in socialist economies were necessarily deficient because if the government owned the means of production, then no prices could be obtained for capital goods as they were merely internal transfers of goods in a socialist system and not "objects of exchange", unlike final goods. Therefore, they were unpriced and hence the system would be necessarily inefficient since the central planners would not know how to allocate the available resources efficiently. This led him to write "that rational economic activity is impossible in a socialist commonwealth". Business cycles The Austrian theory of the business cycle (ABCT) focuses on banks' issuance of credit as the cause of economic fluctuations. Although later elaborated by Hayek and others, the theory was first set forth by Mises, who posited that fractional reserve banks extend credit at artificially low interest rates, causing businesses to invest in relatively roundabout production processes which leads to an artificial "boom". Mises stated that this artificial "boom" then led to a misallocation of resources which he called "malinvestment" - which eventually must end in a "bust". Mises surmised how government manipulation of money and credit in the banking system throws savings and investment out of balance, resulting in misdirected investment projects that are eventually found to be unsustainable, at which point the economy has to rebalance itself through a period of corrective recession. Austrian economist Fritz Machlup summarized the Austrian view by stating, "monetary factors cause the cycle but real phenomena constitute it." For Austrians, the only prudent strategy for government is to leave money and the financial system to the free market's competitive forces to eradicate the business cycle's inflationary booms and recessionary busts, allowing markets to keep people's saving and investment decisions in place for well-coordinated economic stability and growth. A Keynesian would suggest government intervention during a recession to inject spending into the economy when people will not. However, the heart