asked the Secretary of State for Employment whether he is satisfied with the system of seasonal adjustment currently applied to the figures for unemployment and vacancies published by his Department; and whether he will make a statement on the possible disturbances to the published seasonally adjusted estimates stemming from exceptional conditions in the construction industry or any other relevant sectors.
Yes. The seasonal adjustment factors used are brought up to date annually and the method is kept under review. Figures over many years are taken into account in calculating the average variation each month that may be attributed to seasonal influences. Greater weight is given to recent years in order to allow for developments in the seasonal pattern.The unemployment rate in the construction industry in February and May this year was high, but little different from a year ago; it does not appear that this industry, or other sectors, have caused significant erratic disturbance to the seasonally adjusted series.