Title:      Sharp Bounds on the Causal Effects in Randomized
Experiments with ``Truncation-by-Death''

Authors:    Kosuke Imai

Entrydate:  2007-08-23 20:28:05

Keywords:   Average treatment effect, Causal inference, Direct
and indirect effect, Identification, Principal stratification,
Quantile treatment effect.

Abstract:   Many randomized experiments suffer from the
``truncation-by-death'' problem where potential outcomes are not
defined for some subpopulations. For example, in medical trials,
quality-of-life measures are only defined for surviving
patients, and various skip-pattern questions are analyzed in
social science survey experiments. In this paper, I
derive the sharp bounds on causal effects under various
assumptions. My identification analysis is based on the idea
that the ``truncation-by-death'' problem can be formulated as
the contaminated
data problem. The proposed analytical techniques can be applied
to other settings in causal inference including the estimation
of direct and indirect effects and the analysis of three-arm
randomized
experiments with noncompliance.

http://polmeth.wustl.edu/retrieve.php?id=719