Normal approximation for exponential random graphs

The question of whether the central limit theorem (CLT) holds for the total number of edges in exponential random graph models (ERGMs) in the subcritical region of parameters has remained an open problem. In this paper, we establish the CLT in a subset of the subcritical region known as Dobrushin's uniqueness region. As a result of our proof, we also derive a convergence rate for the CLT and an explicit formula for the asymptotic variance. To establish our main result, we develop Stein's method for the normal approximation for general functionals of nonlinear exponential families of random variables, which is of independent interest. In addition to ERGM, our general theorem can also be applied to other models.