The AIA’s monthly Architecture Billings Index (ABI) for March came in at a score of 47.8, a 2.5-point decrease from the previous month’s score of 50.3. It was the first time in which the metric entered negative territory in 25 months. The ABI is a leading economic indicator of construction activity in the U.S. and reflects a nine- to 12-month lead time between architecture billings and construction spending nationally, regionally, and by project type. A score above 50 represents an increase in billings from the previous month, while a score below 50 represents a contraction.