The production function approach to the Belgian output gap, estimation of a multivariate structural time series model

A multivariate structural time series model is applied to the factor inputs of a production function to estimate the Belgian output gap. The number of independent cycles and the frequencies are not restricted a priori. Phase shifts are introduced to allow for leads and lags. Over 1983-2004, a 3.5 years periodicity is found in the cycles. The cycles in the participation and unemployment rates are negligible. Two independent cycles hide behind the cycles of the other variables: hours, TFP and capacity utilization. Phase shifts are significant, with hours leading by as much as 3 quarters and capacity utilization lagging.