Early Keynesianism and monetarism Up to the 1960s, many
Keynesian economists ignored the possibility of stagflation, because history suggested high unemployment correlated with low inflation, and vice versa (the
Phillips curve). The idea was that high demand for goods drives up prices and encourages firms to hire more; and high employment raises demand. However, in the 1970s and 1980s, when stagflation occurred, it became clear that the relationship between inflation and employment levels was not necessarily stable: that is, the Phillips relationship could shift. Macroeconomists became more sceptical of Keynesian theories, and Keynesians reconsidered their ideas in search of an explanation for stagflation. Explanations for the shift of the Phillips curve were initially provided by the
monetarist economist
Milton Friedman, and also by
Edmund Phelps. Both argued that when workers and firms expect more inflation, the Phillips curve shifts up (meaning that more inflation occurs at any given level of unemployment). In particular, they suggested that if inflation lasted for several years, workers and firms would start to take it into account during wage negotiations, causing workers' wages and firms' costs to rise more quickly, thus further increasing inflation. While this idea was a criticism of early Keynesian theories, it was gradually accepted by most Keynesians, and has been incorporated into
New Keynesian economic models.
Neo-Keynesianism Neo-Keynesian theory distinguished two distinct kinds of inflation:
demand-pull (caused by shifts of the aggregate demand curve) and cost-push (caused by shifts of the aggregate supply curve). Stagflation, in this view, is caused by
cost-push inflation. Cost-push inflation occurs when some force or condition increases the costs of production. This could be caused by government policies (such as taxes) or from purely external factors such as a shortage of natural resources or an act of war.
Contemporary Keynesian analyses argue that stagflation can be understood by distinguishing factors that affect
aggregate demand from those that affect
aggregate supply. While monetary and fiscal policy can be used to stabilise the economy in the face of aggregate demand fluctuations, they are not very useful in confronting aggregate supply fluctuations. In particular, an adverse shock to aggregate supply, such as an increase in oil prices, can give rise to stagflation.
Supply theory Fundamentals Supply theories are based on the neo-Keynesian cost-push model and attribute stagflation to large disruptions to the supply side of the supply-demand market equation, such as when there is a sudden scarcity of key commodities, natural resources, or the
natural capital needed to produce goods and services. In this view, stagflation is thought to occur when there is an adverse
supply shock (for example, a sudden increase in the price of
oil or a new tax) that causes a subsequent jump in the "cost" of goods and services (often at the wholesale level). In technical terms, this leads to contraction or negative shift in an economy's aggregate
supply curve. In the resource scarcity scenario (Zinam 1982), stagflation results when a restricted supply of raw materials inhibits economic growth. That is, when the supply of basic materials (fossil fuels (energy), minerals, agricultural land in production, timber, etc.) decreases and/or cannot rise fast enough to respond to demand. The resource shortage may be real or relative due to factors such as taxes or bad monetary policy influencing the "cost" or availability of raw materials. This is consistent with the cost-push inflation factors in neo-Keynesian theory (above). After supply shock occurs, the economy tries to maintain momentum. That is, consumers and businesses begin paying higher prices to maintain their level of demand. The central bank may exacerbate this by increasing the money supply, by lowering interest rates for example, in an effort to combat a recession. The increased money supply props up the demand for goods and services, though demand would normally drop during a recession. In the Keynesian model, higher prices prompt increases in the supply of goods and services. However, during a supply shock (i.e., scarcity, "bottleneck" in resources, etc.), supplies do not respond as they normally would to these price pressures. So, inflation jumps and output drops, producing stagflation.
Explaining the 1970s stagflation Following
Richard Nixon's imposition of
wage and price controls on 15 August 1971, an initial wave of cost-push shocks in commodities were blamed for causing spiraling prices. The second major shock was the
1973 oil crisis, when the Organization of Petroleum Exporting Countries (
OPEC) constrained the worldwide supply of oil. Both events, combined with the overall
energy shortage that characterised the 1970s, resulted in actual or relative scarcity of raw materials. The price controls resulted in shortages at the point of purchase, causing, for example, queues of consumers at fuelling stations and increased production costs for industry. ==Recent views==