boiwsa: An R Package for Seasonal Adjustment of Weekly Data

This article introduces the R package boiwsa for the seasonal adjustment of weekly data based on the discounted least squares method. It provides a user-friendly interface for computing seasonally adjusted estimates of weekly data and includes functions for creation of country-specific prior adjustment variables, as well as diagnostic tools to assess the quality of the adjustments. The utility of the package is demonstrated through two case studies: one based on US data of gasoline production characterized by a strong trend-cycle and dominant intra-yearly seasonality, and the other based on Israeli data of initial unemployment claims with two seasonal cycles (intra-yearly and intra-monthly) and the impact of two moving holidays.