Weather-Adjusting Economic Data

摘要

This paper proposes and implements a statistical methodology for adjusting employment data for the effects of deviations in weather from seasonal norms. This is distinct from seasonal adjustment, which controls only for the normal variation in weather across the year. We simultaneously control for both of these effects by integrating a weather adjustment step in the seasonal adjustment process. We use several indicators of weather, including temperature and snowfall. We find that weather effects can be important, shifting the monthly payroll change number by more than 100,000 in either direction. The effects are largest in the winter and early spring months and in the construction sector. A similar methodology is constructed and applied to data in the national income and product accounts (NIPA), although the manner in which NIPA data are reported makes it impossible to integrate weather and seasonal adjustments fully.