On the Robustness of Economic Models

We investigate the different ways in which the results of theoretical models can be ‘robust’. We identify three kinds of ‘robustness’: (1) robustness to changes in the model’s idealisations; (2) robustness to changes in the ‘background’ conditions; (3) robustness to changes in the implied causal mechanism. Each of these is discussed and illustrated by means of examples from economic practice.