TY - CHAP AB - Abstract Heavy-tailed distributions present a tough setting for inference. They are also common in industrial applications, particularly with internet transaction datasets, and machine learners often analyze such data without considering the biases and risks associated with the misuse of standard tools. This chapter outlines a procedure for inference about the mean of a (possibly conditional) heavy-tailed distribution that combines nonparametric analysis for the bulk of the support with Bayesian parametric modeling – motivated from extreme value theory – for the heavy tail. The procedure is fast and massively scalable. The work should find application in settings wherever correct inference is important and reward tails are heavy; we illustrate the framework in causal inference for A/B experiments involving hundreds of millions of users of eBay.com. VL - 40B SN - 978-1-83867-419-9, 978-1-83867-420-5/0731-9053 DO - 10.1108/S0731-90532019000040B008 UR - https://doi.org/10.1108/S0731-90532019000040B008 AU - Lopes Hedibert Freitas AU - Taddy Matthew AU - Gardner Matthew PY - 2019 Y1 - 2019/01/01 TI - Scalable Semiparametric Inference for the Means of Heavy-tailed Distributions T2 - Topics in Identification, Limited Dependent Variables, Partial Observability, Experimentation, and Flexible Modeling: Part B T3 - Advances in Econometrics PB - Emerald Publishing Limited SP - 141 EP - 156 Y2 - 2024/04/19 ER -