Before revision:  To this aim  we develop a numerical framework which allows one to efficiently compute the fair fee value of a contract. Results show that accounting for both taxation and stochastic interest rate has determinant effects on the behavior of the policy holder and on the cost of GMWB contracts  .
After revision:  To this aim we develop a numerical framework which allows one to efficiently compute the fair fee value of a policy. Numerical results show that accounting for both taxation and stochastic interest rate has determinant effects on the behavior of the policy holder and on the cost of GMWB contracts .