Architecture Billings Index
From the American Institute of Architects: "The Architecture Billings Index is derived from a monthly “Work-on-the-Boards” survey and produced by the AIA Economics & Market Research Group. Based on a comparison of data compiled since the survey’s inception in 1995 with figures from the Department of Commerce on Construction Put in Place, the findings amount to a leading economic indicator that provides an approximately nine to twelve month glimpse into the future of nonresidential construction activity.
Source: Wikipedia — Architecture Billings Index (CC BY-SA 4.0)