You are here:
Vanderbilt Biostatistics Wiki
>
Main Web
>
Seminars
>
WednesdaySeminarSeries
>
FanLi12Feb2020
(14 Jan 2020,
TawannaPeters
)
(raw view)
E
dit
A
ttach
%HEAD{ NAME="Fan Li, !PhD" AFFILIATION="Associate Professor, Duke University Department of Statistical Science" TITLE="Introducing Overlap Weights in Causal Inference" IMAGELINK="https://forge.duke.edu/sites/default/files/styles/medium/public/thumbnails/image/Fan.jpg?itok=oIONq_iN" }% Covariate balance is crucial for unconfounded descriptive or causal comparisons. However, lack of balance is common in observational studies. We consider weighting strategies for balancing covariates. We define a general class of weights, the balancing weights, that balance the weighted distributions of the covariates between treatment groups. These weights incorporate the propensity score to weight each group to an analyst-selected target population. This class unifies existing weighting methods, including commonly used weights such as inverse-probability weights as special cases. General large-sample results on nonparametric estimation based on these weights are derived. We further propose a new weighting scheme, the overlap weights, in which each unit's weight is proportional to the probability of that unit being assigned to the opposite group. The overlap weights are bounded, and minimize the asymptotic variance of the weighted average treatment effect among the class of balancing weights. The overlap weights also possess a desirable small-sample exact balance property, based on which we propose a new method that achieves exact balance for means of any selected set of covariates. Extensions to multiple treatments and subgroup analysis will also be discussed. %TAIL{DATE="12 February 2020"}% <!-- * Set HEAD = <div class="w3-card-2" id="task" style="max-width:750px; margin-left: 0px;"> <header class="w3-container w3-blue" style="padding:40px"><h1>Biostatistics Weekly Seminar</h1><br><h2 style="color:white;">%TITLE%<br><br>%NAME%<br>%AFFILIATION%</h2></header><div class="w3-container" style="padding:40px"><IMG SRC=%IMAGELINK% align="left" id="mug"/> * Set TAIL = <br><h3>MRBIII, Room 1220<br>%DATE%<br>1:30pm</h3></div></div><br>[[%TOPIC%Itinerary][Speaker Itinerary]] --> <style> .w3-card-2,.w3-example{box-shadow:0 2px 4px 0 rgba(0,0,0,0.16),0 2px 10px 0 rgba(0,0,0,0.12)!important} .w3-blue,.w3-hover-blue:hover{color:#fff!important;background-color:#2196F3!important} .w3-container{padding:0.01em 16px} .foswikiTopic {font-family: 'Open Sans', sans-serif;} /* Removes location hierarchy (usually written in grey text) */ .patternHomePath {display:none;} /* Removes bar with edit and attach buttons and location hierarchy */ .patternTop{display:none;} h1, h2, h3, h4, h5, h6{font-family: 'Montserrat','Open Sans', sans-serif;font-weight:700;} h1, h2, h3, h4, h5, h6{color:#bf1735;} h1:first-of-type{color:#2a3e6e;margin-bottom:25px;margin-top:5px;} .foswikiImage{margin-left:-9px;} img#mug{padding-right: 40px; padding-bottom:25px; height:250px;} </style>
E
dit
|
A
ttach
|
P
rint version
|
H
istory
: r1
|
B
acklinks
|
V
iew topic
|
Edit
w
iki text
|
M
ore topic actions
Topic revision: r1 - 14 Jan 2020,
TawannaPeters
Main
Department Home Page
Biostatistics Graduate Program
Vanderbilt University Medical Center
Main Web
Main Web Home
Search
Recent Changes
Changes
Topic list
Biostatistics Webs
Archive
Main
Sandbox
System
Register
|
Log In
Copyright © 2013-2022 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding Vanderbilt Biostatistics Wiki?
Send feedback