The prevailing wisdom that aggregate demand shocks determine short-run cyclical fluctuations around a supply-determined equilibrium growth rate and an associated equilibrium unemployment rate (or NAIRU) has been called into question by various strands of literature over the last few decades. Specifically, a recently revived literature on hysteresis finds significant persistence in the effects of negative aggregate demand shocks (e.g. Blanchard et al. 2015; Fatás and Summers 2016; Martin et al. 2015).
This paper aims to assess this tendency to return to a supply-determined potential output, independent of aggregate demand, after episodes of demand expansion. In line with the hysteresis literature, we assess the persistence of aggregate demand effects on key macroeconomic outcomes. However, in contrast with much of that literature, we assess whether persistence is detected also in instances of demand expansion. We study 94 episodes of demand expansion in 34 OECD countries between 1960 and 2015. We look at the sum of primary public expenditure and exports, a variable we call ‘autonomous demand’. We define an expansion as a large yearly percentage increase in autonomous demand, ‘large’ meaning greater than a standard deviation above the country mean. We analyze the impact of these expansions on key macroeconomic outcomes in the subsequent decade, using various techniques to deal with endogeneity. We employ two main approaches: a dynamic two-way fixed-effects model, analogous to a standard difference-in-differences estimation; and a propensity score-based specification which explicitly models selection bias.
We find a highly significant persistent effect on the GDP level: a one-off expansion in our autonomous demand variable by (an average of) 5% is associated 10 years later with a GDP level around 3% higher than in the control group, with no sign of mean reversion. We also document strong persistent effects on capital stock, employment and participation rates. Effects on productivity and the unemployment rate are also strong and quite persistent, but evidence regarding their permanence is more mixed. We do not find that expansions, on average, cause high or accelerating inflation.
Our results lead us to ask whether hysteresis should be considered a distortion in the working of market economies that holds only in specific circumstances – as the mainstream literature has generally suggested – or whether it is, in fact, a pervasive phenomenon which holds most of the time.