  The problem of pricing Bermudan options using Monte Carlo and a nonparametric
regression is considered. We derive optimal non-asymptotic bounds for a lower
biased estimate based on the suboptimal stopping rule constructed using some
estimates of continuation values. These estimates may be of different nature,
they may be local or global, with the only requirement being that the
deviations of these estimates from the true continuation values can be
uniformly bounded in probability. As an illustration, we discuss a class of
local polynomial estimates which, under some regularity conditions, yield
continuation values estimates possessing this property.
