About: Divine coincidence

In economics, divine coincidence refers to the property of New Keynesian models that there is no trade-off between the stabilization of inflation and the stabilization of the welfare-relevant output gap (the gap between actual output and efficient output) for central banks. This property is attributed to a feature of the model, namely the absence of real imperfections such as real wage rigidities. Conversely, if New Keynesian models are extended to account for these real imperfections, divine coincidence disappears and central banks again face a trade-off between inflation and output gap stabilization. The definition of divine coincidence is usually attributed to the seminal article by Olivier Blanchard and Jordi Galí in 2007.