  This paper proposes a causal decomposition framework for settings in which an
initial regime randomization influences the timing of a treatment duration. The
initial randomization and treatment affect in turn a duration outcome of
interest. Our empirical application considers the survival of individuals on
the kidney transplant waitlist. Upon entering the waitlist, individuals with an
AB blood type, who are universal recipients, are effectively randomized to a
regime with a higher propensity to rapidly receive a kidney transplant. Our
dynamic potential outcomes framework allows us to identify the pre-transplant
effect of the blood type, and the transplant effects depending on blood type.
We further develop dynamic assumptions which build on the LATE framework and
allow researchers to separate effects for different population substrata. Our
main empirical result is that AB blood type candidates display a higher
pre-transplant mortality. We provide evidence that this effect is due to
behavioural changes rather than biological differences.
