activity
20192022
most citedSufficient Representations for Categorical Variables

11 citations · 25 across the 5 of their papers we have counts for

collaborators

6 papers

econ.EM2022★ 7 cited

Contextual Bandits in a Survey Experiment on Charitable Giving: Within-Experiment Outcomes versus Policy Learning

Susan Athey, Undral Byambadalai, Vitor Hadad +3

We design and implement an adaptive experiment (a ``contextual bandit'') to learn a targeted treatment assignment policy, where the goal is to use a participant's survey responses…

stat.ML2021

Off-Policy Evaluation via Adaptive Weighting with Data from Contextual Bandits

Ruohan Zhan, Vitor Hadad, David A. Hirshberg +1

It has become increasingly common for data to be collected adaptively, for example using contextual bandits. Historical data of this type can be used to evaluate other treatment as…

cs.LG2021★ 4 cited

Adapting to Misspecification in Contextual Bandits with Offline Regression Oracles

Sanath Kumar Krishnamurthy, Vitor Hadad, Susan Athey

Computationally efficient contextual bandits are often based on estimating a predictive model of rewards given contexts and arms using past data. However, when the reward model is…

cs.LG2020★ 3 cited

Tractable contextual bandits beyond realizability

Sanath Kumar Krishnamurthy, Vitor Hadad, Susan Athey

Tractable contextual bandit algorithms often rely on the realizability assumption - i.e., that the true expected reward model belongs to a known class, such as linear functions. In…

stat.ML2019

Confidence Intervals for Policy Evaluation in Adaptive Experiments

Vitor Hadad, David A. Hirshberg, Ruohan Zhan +2

Adaptive experiment designs can dramatically improve statistical efficiency in randomized trials, but they also complicate statistical inference. For example, it is now well known…

stat.ML2019★ 11 cited

Sufficient Representations for Categorical Variables

Jonathan Johannemann, Vitor Hadad, Susan Athey +1

Many learning algorithms require categorical data to be transformed into real vectors before it can be used as input. Often, categorical variables are encoded as one-hot (or dummy)…