| Abstract: |
We propose a “Cluster-Squared” algorithm to efficiently combine economic forecasts.
Forecasters are first clustered into groups, which implicitly maximize in-group similarities
and inter-group disagreement. This step resolves the weighting instability problem in most
dynamic weighting schemes. Secondly, to account for non-stationarity in the time series, we
allow the groups’ combination weights to be state-dependent. The states are uncovered using
subsequence clustering. Experimental results show that the algorithm has smaller prediction
error compared with median forecasts for a broad set of economic indicators in the Survey
of Professional Forecasters (Federal Reserve bank of Philadelphia). Our algorithm also compare
favorably against other popular dynamic weighting algorithms. |