In a one-state one-control variable Quadratic Linear Problem, I examine the effect of an increase in the multiplicative uncertainty on the use of the control variable. In contrast with previous studies, this model considers a stochastic constant term in the transition equation. I found that the...

In this essay, it is shown that in the Hoel and Karp (2001) model of global warming, the optimal response of taxes for a stock pollutant with mutiplicative uncertainty is opposite when the control variable is pollution taxes instead of emissions. In this case, the election of control variable...

In this paper an analytical framework using robust control was developed for the one-state and one-control variable model to examine the response of the control to changes in the "free" parameter. However, in contrast to Gonzalez and Rodriguez (2003), the sign of the ``free" parameter in the...