# Tag Info

Actually, your result that the gradient is 0 is correct given your formulation. Indeed, that is why one might have believed that the deterministic policy gradient didn't exist. The term $\nabla_{\theta}\log \pi(a \, | \, s)$ is a type of gradient estimator known as a likelihood ratio, and it assumes that the support of $\pi$ does not depend on $\theta$. In ...