The Surrogate Index: Combining Short-Term Proxies to Estimate Long-Term Treatment Effects More Rapidly and Precisely

The Surrogate Index: Combining Short-Term Proxies to Estimate Long-Term Treatment Effects More Rapidly and Precisely
(with Susan Athey, Guido W. Imbens and Hyunseung Kang), NBER Working Paper No. 26463 (November 2019)