effects in the short run, neoclassical and neo-Keynesian economists tend to agree that there are no long-run effects from changing the money supply. Therefore, even economists who consider themselves neo-Keynesians usually believe that in the long run, money is neutral. In other words, while neoclassical and neo-Keynesian models are often seen as competing points of view, they can also be seen as two descriptions appropriate for different time horizons. Many mainstream textbooks today treat the neo-Keynesian model as a more appropriate description of the economy in the short run, when prices are 'sticky', and treat the neoclassical model as a more appropriate description of the economy in the long run, when prices have sufficient time to adjust fully. Therefore, while mainstream economists today might often attribute short periods of stagflation (not more than a few years) to adverse changes in supply, they would not accept this as an explanation of very prolonged stagflation. More prolonged stagflation would be explained as the effect of inappropriate government policies: excessive regulation of product markets and labour markets leading to long-run stagnation, and excessive growth of the money supply leading to long-run inflation. Alternative views As differential accumulation Political economists Jonathan Nitzan and Shimshon Bichler have proposed an explanation of stagflation as part of a theory they call differential accumulation, which says firms seek to beat the average profit and capitalisation rather than maximise. According to this theory, periods of mergers and acquisitions oscillate with periods of stagflation. When mergers and acquisitions are no longer politically feasible (governments clamp down with anti-monopoly rules), stagflation is used as an alternative to have higher relative profit than the competition. With increasing mergers and acquisitions, the power to implement stagflation increases. Stagflation appears as a societal crisis, such as during the period of the oil crisis in the 70s and in 2007 to 2010. Inflation in stagflation, however, does not affect all firms equally. Dominant firms are able to increase their own prices at a faster rate than competitors. While in the aggregate no one appears to profit, differentially dominant firms improve their positions with higher relative profits and higher relative capitalisation. Stagflation is not due to any actual supply shock, but because of the societal crisis that hints at a supply crisis. It is mostly a 20th and 21st century phenomenon that has been mainly used by the "weapondollar-petrodollar coalition" creating or using Middle East crises