Moving Average (MA) Models:
Moving average (MA) models are used in time series analysis to describe stationary time series . The MA-models represent time series that are generated by passing the white noise through a non-recursive linear filter .
A moving average model of a random process in discrete time is defined by the following expression:
are the coefficients of the linear non-recursive filter;
is the order of the MA-model;
are elements of the (input) white noise;
are the output uncorrelated errors.