This paper argues that it is wrong to require that regressing the outputs of a trace-driven simulation on the observed real outcomes should give a 45° (unit slope) line through the origin (zero intercept). This note proposes instead an alternative requirement: the responses of the simulated and...

This paper proves that it is wrong to require that regressing a model's outputs on the observed real outcomes give a 45 line through the origin (unit slope, zero intercept). Therefore this paper proposes an alter-native requirement: the responses of the model and the real system should have the...