"Modern statistical theory originated in England, and is today advancing faster there than in any other country." So Harold Hotelling (1930a, 186) informed the American Statistical Association after a visit in 1929. Hotelling traced the origins to Karl Pearson and attributed the current progress to R. A. Fisher. A few years later there were two new theorists to watch, Jerzy Neyman and Abraham Wald, Fisher's main rivals/successors in the theory of statistical inference. I will be considering these four and how they interacted with the econometricians-with H. L. Moore, Mordecai Ezekiel, Henry Schultz, Tjalling Koopmans, and Trygve Haavelmo especially. I also note some statisticians who might have been, but were not, the econometricians' statisticians.Research in the history of econometrics has concentrated-naturally enough-on the distinctive concepts developed by econometricians, "structure" and "identifi cation" being outstanding instances, but the history of econometrics is also a history of using ideas from statistics. These ideas and how they traveled will be my concern; more broadly, I will be considering the way statisticians and econometricians worked together, or,