Respond to Discussion Question 4a


Capital Punishment Deters Crime

 The above general statement is problematic in various ways.  When considered in a cross-sectional study, various threats to the validity of this statement must be considered.  A cross-sectional study of this statement would attempt to answer whether capital punishment, the intervention (X), deters crime, the outcome (Y) (Langbein, 2015).  For this statement to be valid, it must overcome the threats common to cross-sectional studies.  The validity threats that seem to be the most important to consider in answering this question, I believe, are selection or uncontrolled selection and multiple treatment interference (Langbein, 2015).

Selection or Uncontrolled Selection

            Considering various sample groups for the study of causation makes selection or uncontrolled selection a validity threat to this type of study.  For instance, people age out crime.  Therefore, the average age of the sample group could have an effect on whether or not the group even considers the death penalty when choosing not to commit a capital crime.  Additionally, some states do not enforce capital punishment so a decrease in crime in those states would have to be explained in another manner.  There are countries that enforce the death penalty publicly.  In those countries, people are surely aware of the death penalty and it may have a more definite causal effect on a decrease in crime.

Multiple Treatment Interference

            Multiple treatment interference is a validity threat to the study of causality between capital punishment and crime deterrence.  The ultimate deterrence for crime could be considered to be incapacitation.  Being imprisoned incapacitates the prisoner from committing crime in the public arena.  Many death row inmates remain on death row for years, some even die while waiting to be executed.  This incapacitation could be considered to be an alternative treatment.  Although the execution has not taken place, the criminal is not able to continue a life of crime.  I suppose that this incapacitation could be considered to be a secondary effect of the death penalty.  So, consider someone outside of prison who makes the choice to refrain from continuing a life of crime.  As was already discussed, people age out of crime and there are many other variables that can have an effect on would-be criminals.  Family life, affiliation with positive role models, and arrest and rehabilitation can all affect a person’s decision to live a life free from criminal activity.  Although many, if not all, are aware of the possibility of the death penalty, it may play a small role, if any, in the decision to live crime-free.


Langbein, (2015). Public Program Evaluation: A Statistical Guide. Taylor and Francis. Kindle Edition.

Make sure you write directly to the original poster.  In what ways do you agree or disagree that the validity issues in the scenarios of causal claim selected by your colleagues are the most important? Provide a rationale, including examples or references.  APA format.  In text citations.

    • 4 years ago
    • 10

    Purchase the answer to view it

    • attachment