3.2.3. Residual Analysis

We carry out goodness-of-fit through residual analysis. In particular, we consider the generalized Cox–Snell residual, which is given by

$$r^{\rm cs} = -\ln \hat{S}(\mathbf{x}\_i | \mathcal{F}\_{i-1}),\tag{22}$$

,

where *S* <sup>ˆ</sup>(*xi*|F*<sup>i</sup>*−<sup>1</sup>) denotes the fitted conditional survival function. When the model is correctly specified, the Cox–Snell residual has a unit exponential (EXP(1)) distribution; see Bhatti (2010).
