  We compute the expected value of the Kullback-Leibler divergence to various
fundamental statistical models with respect to canonical priors on the
probability simplex. We obtain closed formulas for the expected model
approximation errors, depending on the dimension of the models and the
cardinalities of their sample spaces. For the uniform prior, the expected
divergence from any model containing the uniform distribution is bounded by a
constant $1-\gamma$, and for the models that we consider, this bound is
approached if the state space is very large and the models' dimension does not
grow too fast. For Dirichlet priors the expected divergence is bounded in a
similar way, if the concentration parameters take reasonable values. These
results serve as reference values for more complicated statistical models.
