This paper explores the implications of time varying volatility for optimal monetary policy and the measurement of welfare costs. We show how macroeconomic models with linear and quadratic state dependence in their variance structure can be used for the analysis of optimal policy within the...

This paper shows that forward default intensities in the Black and Cox (1976) model of corporate default can be expressed in terms of the Mills Ratio (Mills, 1926). The behaviour of the forward default intensity and hence the survivorship functions then follows from inequalities that are...