Short-lived supply shocks to potential growth
Potential growth, or the non-inflationary rate of growth in output, is generally viewed as a slow-moving and smooth process. This implies that all the sudden changes in real gross domestic product (GDP), regardless of origin, are reflected in the output gap. There are, however, short-lived supply shocks. Recent examples include the platinum-sector strike of 2014 and the drought of 2015/16 that are more accurately identified as temporary shifts in potential growth. We update the South African Reserve Bank’s current, finance-neutral, estimates of potential growth to account for these short-lived supply shocks. We compare the supply shocks, that should shift potential growth rather than the output gap generated from the model, to a structural vector autoregression (SVAR) model. The resulting output gap more accurately reflects a measure of demand pressures in the economy at any given point in time. The output gap is not as wide as previously estimated after 2015.