After three months of improvements, the American Institute of Architects' (AIA) Architecture Billings Index (ABI) has slipped by nearly three points. The May 2010 ABI rating was 45.8, down from 48.4 in April. (Read about April's ABI and other economic indicators.) May's new projects inquiry index was 55.5, down from April's score of 59.6.

According to Kermit Baker, Ph.D., Hon. AIA, this decline was not expected based on the previous three months' improvements and signs that the economy is recovering. He notes that the flow of credit is still tightly controlled by extremely cautious lending institutions, despite the apparent demand for and potential success of new projects.

May's regional breakdown shows that the Northeast reported a score of 50.6, followed by the Midwest (48.5), South (45.9), and West (42.9). The commercial/industrial sector had a score of 51.3, followed by multifamily residential at 46.9, mixed practice at 46.8, and institutional at 43.4.