The Inflation Reduction Act's credits were followed by a large expansion in domestic solar, wind, storage and battery manufacturing announcements, much of it in states that had not previously hosted such plants. Supporters argue the credits were the reason, since the projects were announced after passage and clustered around eligibility rules. Critics respond that announcements are not factories, that many projects were later cancelled or delayed, and that some investment would have happened as equipment costs fell regardless of tax policy. Separating the credit effect from the cost-curve effect is the central empirical dispute.