ASID IDBI and Inquiries indices will use a seasonal adjustment (SA) calculation beginning with the January 2019 data and report. This adjustment includes changes that are brought about by the seasons themselves, such as home building increases during summer months and increased retail sales during the holiday season.
Seasonal adjustment methodologies have been developed to remove these predictable patterns and reveal a more accurate picture of the underlying changes affecting the data. This is a common feature of most economic data and distorts analysis of underlying strength or weakness of economic trends. Many prominent institutions use a seasonally adjustment calculation when reporting on trends such as the Bureau of Labor Statistics, the U.S. Census, the Federal Reserve, and many universities.