I am trying to understand the coefficients retrieved from running
auto.arima in R on my monthly time series of the annual change in House prices. When doing so, I obtain the following outcome:
Series: AC.HousePrices ARIMA(1,1,1)(0,0,1) with drift Coefficients: ar1 ma1 sma1 drift 0.3243 -0.6592 -0.7892 -6e-04 s.e. 0.1733 0.1333 0.1161 4e-04 sigma^2 estimated as 0.0008257: log likelihood=275.22 AIC=-540.44 AICc=-539.96 BIC=-526.07
To be honest I do not understand why I have two sets of parameters (p,d,q) and (P,D,Q)? The first set (1,1,1) seems to indicate that the series is first-order autoregressive model, nonstationary and with a simple exponential smoothing with drift? What are the second set of values (0,0,1), is it telling me that my series looks yearly seasonal ?