My early academic work was on the Phillips curve and the precision in estimating the concept of a natural rate of unemployment, or the rate of unemployment where inflation stabilises at some level. This rate is now commonly referred to as the Non-Accelerating-Rate-of-Unemployment (NAIRU) and my contribution was one of the first studies to show that the rate was variable and went up and down with the economic cycle, rendering it a meaningless concept for discretionary policy interventions. I extended that work into my PhD and built on much earlier work as a undergraduate to articulate the Job Guarantee idea. The NAIRU is unobservable and there have been various ways to estimate it from actual data. The problem is that these estimates are highly sensitive to the approach – so two researchers can get quite different estimates using the same data. Further, the estimates themselves are subject to large statistical errors meaning that we cannot be sure whether the NAIRU is say 4.5 per cent or 3.5 per cent or 5.5 per cent, say. Such imprecision makes it impossible to use the concept as a guide for monetary policy because if the NAIRU actually existed then ‘full employment’ might be at 3.5 or 5.5 per cent today but next week the estimates might be even wider. When would one want to start changing interest rates in pursuit of inflation stability – when the actual unemployment rate was down to 3.5 per cent or at 5.5 per cent or somewhere in between or at higher or lower unemployment rates, depending on what the models pumped out? You can see the problem. For some years, central bankers went quiet on the use of the NAIRU and stopped publishing their estimates exactly because they knew full well about the imprecision and that policy based on such a vague, difficult to estimate, unobservable would be discredited. That is until now. The RBA is now clearly admitting that their damaging and unnecessary interest rate hikes over the last year and a bit have been driven by the NAIRU. A sham. But a tragedy as well given the RBA’s almost obsession with pushing unemployment up by around 140,000. A shocking indictment of where we have reached as a civilisation.