Ryan Walch is a Senior Economist at Amazon, specializing in causal inference, experimentation, and marketing science. Previously, they were a Postdoctoral Fellow at the University of Alberta and a Ph.D. Candidate at the University of Oregon, where they focused on environmental and energy policy. Ryan holds a Ph.D. and a Master of Science in Economics from the University of Oregon, as well as a Bachelor of Science in Mathematics and Economics from the University of Puget Sound.