CHAPTER 14 Assessing Mechanisms Flashcards
What does estimating an average causal effect tell us?
It tells us that a change in the treatment changes the outcome
The effect may not be direct or proximate and could be the result of a long chain of relationships.
What is the challenge in understanding causal relationships?
Learning about the mechanisms underlying a causal relationship is harder than it seems
We generally cannot just measure potential mechanisms to learn their importance.
What is a mechanism in the context of causal relationships?
A mechanism is an answer to how questions or why questions regarding the effect of a treatment on an outcome.
What is causal mediation analysis?
Causal mediation analysis aims to directly tell us how important a role some mechanism plays in driving a particular effect.
In causal mediation analysis, what is a mediator?
A mediator is a mechanism by which an effect occurs, such as taking AP classes in the example of charter schools and college admission.
What does it mean to control for a variable in a regression analysis?
To control for a variable means to hold it constant in the analysis to isolate the effect of the treatment.
True or False: Controlling for AP classes in a regression analysis purges their effect from the treatment’s effect.
False
Controlling for AP classes does not equate to purging their effect, as it does not account for confounders.
What is a key takeaway regarding identifying important mechanisms?
There is no magical technical or statistical way to identify which mechanisms matter; clear thinking and hard work are required.
What is an intermediate outcome?
An intermediate outcome is a downstream effect of a treatment that can provide hints about mechanisms.
How can testing for intermediate outcomes help understand mechanisms?
It can indicate which intermediate outcomes are affected by the treatment, helping to identify potential mechanisms.
What was the focus of the study by Blattman, Jamison, and Sheridan in Liberia?
The study focused on the effects of cognitive behavioral therapy on at-risk youths to improve economic outcomes and reduce crime.
What did the study in Liberia reveal about self-control skills?
The therapy had little effect on self-control skills, suggesting they are unlikely mechanisms for the observed outcomes.
What features of the cognitive behavioral therapy were found to be effective?
The therapy affected social networks and attitudes toward violence, suggesting these are important mechanisms.
What is the purpose of generating independent theoretical predictions?
To help adjudicate between different potential mechanisms underlying an estimated effect.
What did Anzia and Berry’s study examine?
Whether voters discriminate against women in elections.
What prediction did Anzia and Berry make regarding women in elections?
If there is discrimination, women elected should perform better at their jobs than men due to needing to clear a higher hurdle.
What method did Anzia and Berry use to compare the performance of male and female members of Congress?
They used a difference-in-differences design to account for differences across districts and time periods.
What conclusion was drawn from Anzia and Berry’s findings?
Female members of Congress tend to be more productive than male members, supporting the theory of discrimination.
What phenomenon do Anzia and Berry explore regarding female members of Congress?
Women perform better in Congress than men, suggesting potential voter discrimination against female candidates.
This suggests that women may have to clear a higher hurdle to be elected.
What hypothesis do Anzia and Berry test regarding performance differences in Congress?
The gap in performance between elected women and men should be greater in more conservative districts.
This is based on the idea that conservative districts may discriminate more against female candidates.
How do Anzia and Berry differentiate the performance of widows in Congress?
Widows do not perform better than male members of Congress and perform worse than female candidates elected independent of their spouses.
This suggests that the performance advantage seen in elected women is not due to a lack of discrimination faced by widows.
What is a significant conclusion from Anzia and Berry’s study?
The study provides a model for understanding causal mechanisms through a combination of theory and data analysis.
It highlights the importance of testing multiple predictions from a theoretical framework.
What did Gerber, Green, and Larimer’s study on social pressure and voting demonstrate?
Mailing postcards informing voters of their neighbors’ voting behavior increased voter turnout by 8 percentage points.
This shows the impact of social pressure on voter behavior.
What was the purpose of the second type of postcard in Gerber, Green, and Larimer’s experiment?
To isolate the social pressure mechanism by only informing recipients about their household members’ voting behavior.
This postcard increased turnout by 5 percentage points, indicating the importance of social pressure.
