ISM / PMI surveys
The ISM Purchasing Managers' Index surveys hundreds of company purchasing managers monthly: are orders, production, hiring, and deliveries improving or worsening? Readings above 50 indicate expansion, below 50 contraction of the sector itself — for the whole economy the line sits lower, in the high 40s, since services usually keep growing.
Soft data, hard record
Surveys feel like opinion, but purchasing managers are reporting actual order flow — they're closer to the ground than GDP. Manufacturing PMI has dipped below 48 ahead of or during nearly every post-war recession; the services version held up longer in goods-led slowdowns like 2015–16.
Strengths and limits
PMIs are fast (first business day of the month) and comprehensive, but they're direction-of-change measures — they say whether things are getting better or worse, not how much. On this site PMI-style data appears through the CFNAI, which incorporates ISM components among its 85 series — breadth over any single survey.