Eb. Dagum et al., A unified view of signal extraction, benchmarking, interpolation and extrapolation of time series, INT STAT R, 66(3), 1998, pp. 245-269
Time series data are often subject to statistical adjustments needed to inc
rease accuracy, replace missing values and/or facilitate data analysis. The
most common adjustments made to original observations are signal extractio
n (e.g. smoothing), benchmarking, interpolation and extrapolation. In this
article, we present a general dynamic stochastic regression model, from whi
ch most of these adjustments can be performed, and prove that the resulting
generalized least square estimator is minimum variance linear unbiased. We
extend current methods to include those cases where the signal follows a m
ixed model (deterministic and stochastic components) and the errors are aut
ocorrelated and heteroscedastic.