We discuss the problem of parameter estimation in nonlinear stochastic
differential equations based on sampled time series. A central message from the
theory of integrating stochastic differential equations is that there exists in
general two time scales, i.e. that of integrating these equations and that of
sampling. We argue that therefore maximum likelihood estimation is
computational extremely expensive. We discuss the relation between maximum
likelihood and quasi maximum likelihood estimation. In a simulation study, we
compare the quasi maximum likelihood method with an approach for parameter
estimation in nonlinear stochastic differential equations that disregards the
existence of the two time scales.Comment: in press: Chaos, Solitons & Fractal