The purpose of this paper is to build a small macro model along the lines of the SARB’s Quarterly Projection Model (QPM). We infer optimal monetary policy rules in terms of interest rate gaps (as defined by the QPM). We investigate flexible inflation targeting augmented with interest rate smoothing and the zero lower bound. We find that between 2000 and 2002 the actual repo rate was below both the strict output gap targeting implied repo rate and the strict inflation targeting implied repo rate. This implies that monetary policy was too accommodative. Similarly, between 2006 and early 2009 (before the global financial crisis), monetary policy appears to have been too accommodative. Interestingly, we find no evidence of periods when monetary policy was too restrictive. We also find that in the case of flexible inflation targeting – since the adoption of the QPM in 2017 – policymakers seem to have placed a bigger weight on inflation than growth.