6. Conclusion
The theory and evidence in Castle, Clements, and Hendry (2013) demonstrated the importance of robustifying forecasts to location shifts, a key source of forecast failure. Regression models, whether based on variables or factors, are equilibrium-correction formulations, so like all EqCMs, are not robust after location shifts, potentially facing systematic forecast failure. We presented a new class of forecasting devices that are robust after location shifts, and analyzed their properties in a variety of settings. For large location shifts, the most adaptable should prove advantageous, but if other problems are present, such as measurement errors at the forecast origin, a smoothed variant may perform better.