About this Release
The concurrent seasonal adjustment methodology was adopted by retail trade in April 2000 and has provided estimates that approach the final series rapidly with no increase in provider burden or operational costs. In this paper the merits of applying the concurrent adjustment methodology to a monthly series are reviewed and the potential advantages for quarterly series discussed. Concurrent adjustment is particularly useful when surveys are undergoing methodological change. A case in point is the integration of business surveys into the Quarterly Economic Activity Survey (QEAS). Concurrent adjustment will be more responsive, than the current seasonal adjustment method, to methodological and questionnaire changes affecting the component survey data, providing consistent and coherent seasonal adjusted data. A simulation on QEAS data shows that there are substantial gains in accuracy for concurrently adjusting quarterly series. We therefore recommend introducing concurrent adjustment to this survey.