In the paper we consider the problem of valuation of American options written
on dividend-paying assets whose price dynamics follow the classical
multidimensional Black and Scholes model. We provide a general early exercise
premium representation formula for options with payoff functions which are
convex or satisfy mild regularity assumptions. Examples include index options,
spread options, call on max options, put on min options, multiply strike
options and power-product options. In the proof of the formula we exploit close
connections between the optimal stopping problems associated with valuation of
American options, obstacle problems and reflected backward stochastic
differential equations