Article
m a ProcessThe m process is represented by MA(q) it happens to be a general finite order procedure that is an autoregressive variant of a stationary line with covariance. It is stationary in the sense that the current conditional expectation is solely a function of the lagged and current unobserved shocks. This function is called the partial autocorrelation.
Contrary to AR processes and AR processes, the MA(q) process does not have a distinct MA polynomial. In fact, there are numerous possibilities for MA(q) polynomials lag operator that may be stationary and possess the same asymptotic characteristics.
To ensure that the process is causal in nature, it is common practice to impose invertibility restrictions on the MA polynomial. This ensures that only previous events (not future ones) predict current events.