The Vidale-Wolfe advertising model is a singular optimal control probl
em with a non negative control. Sufficient conditions on a generalized
time-varying market, for which a solution can be found, are given. Ti
me is parametrized to describe impulsive optimal trajectories in a con
ventional manner. The solution is then found and verified by using the
Hamilton-Jacobi-Bellman equation on the parametrized problem. (C) 199
7 John Wiley & Sons, Ltd.