m a processThe m a process, referred to as MA(q), is the general finite-order process that happens to be an autoregressive representation of a stationary series. It is stationary in the sense that the current expectation of conditional events is solely a https://oneonlineco.com/step-by-step-guide-to-choosing-a-virtual-data-room-in-2024/ function of the current and lagged unobserved shocks. This is known as the partial autocorrelation.
MA(q) MA(q) does not have an individual MA polynomial like AR processes. There are a variety of MA(q), lag operator polynomials that may be stationary and have the same asymptotic properties.
It is therefore conventional to impose invertibility limitations on the MA polynomial to guarantee that the process is causal. This ensures that only previous events (not future ones) can predict the future.