<P> 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 . </P> <P> 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, doesn't 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 be profiting, 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 for the benefit of pecuniary interests . </P> <P> Demand - pull stagflation theory explores the idea that stagflation can result exclusively from monetary shocks without any concurrent supply shocks or negative shifts in economic output potential . Demand - pull theory describes a scenario where stagflation can occur following a period of monetary policy implementations that cause inflation . This theory was first proposed in 1999 by Eduardo Loyo of Harvard University's John F. Kennedy School of Government . </P> <P> Supply - side economics emerged as a response to US stagflation in the 1970s . It largely attributed inflation to the ending of the Bretton Woods system in 1971 and the lack of a specific price reference in the subsequent monetary policies (Keynesian and Monetarism). Supply - side economists asserted that the contraction component of stagflation resulted from an inflation - induced rise in real tax rates (see bracket creep) </P>

In which of the following time periods did these united states experience stagflation