This paper constructs a model for the evolution of a risky security that is consistent with a set of observed call option price. It explicitly treats the fact that only a discrete data set can be observed in practice, The framework is general and allows for state dependent volatility and jumps.

In this study we evaluate some effects of the reform of the welfare system that took place in the Province of Quebec in August 1989. This reform abolished the discrimination based on age that applied to the benefits single individuals and childless couples below the age of 30 were entittled to.