Add to ORKGThe advent of ’rational expectation hypothesis’ (REH) in 1970’s sparked intense debate on the effectiveness of discretionary aggregate demand policies in influencing real economic activities. In line with this, the Lucas Critique (Lucas, 1976), that embodies the REH, questions the efectiveness of policy rule that frequently adopted in the set up of monetary policy. This commentary revisited the foundations of Lucas Critique and empirical studies reported by Habibullah, Azali dan Baharumshah (2001) (in short, HAB) on the validity of the critique within the Malaysian economy. The Lucas Critique is explained in greater detail based on an economic model that incorporates the behaviours of economic agents that form their expectation rationall...