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.
What challenge do scholars face when studying economic conditions and violent conflict?
Determining the causal relationship between economic conditions and violent conflict is complex due to confounding factors.
The relationship can be influenced by various factors, making it hard to establish causation.
What research design do scholars use to study the effect of economic conditions on violence?
Difference-in-differences design using commodity price shocks.
This allows for comparing violence in areas with different economic conditions over time.
What did the findings from studies on commodity price shocks reveal about economic conditions and violence?
Results were inconsistent; sometimes positive economic shocks reduced violence, sometimes increased it, and sometimes had no effect.
This suggests multiple mechanisms at play.
What two opposing mechanisms did Dal Bo and Dal Bo identify regarding economic conditions and conflict?
- Opportunity cost mechanism: Better economic conditions reduce the likelihood of fighting.
- Predation mechanism: Better economic conditions increase the benefits of fighting.
These mechanisms can pull in opposite directions.
What did Dube and Vargas’s study in Colombia find regarding coffee and oil industries?
Positive shocks to coffee prices reduced conflict in coffee-intensive areas, while positive shocks to oil prices increased conflict in oil-intensive areas.
This supports the idea that economic conditions influence conflict through multiple mechanisms.
What is the significance of understanding competing mechanisms in economic conditions and conflict?
Different mechanisms can lead to opposite effects on conflict, indicating that economic aid must be aligned with job opportunities to be effective.
Economic aid that increases resources without providing jobs may exacerbate conflict.
What is a mediator in research terms?
A feature of the world that is affected by the treatment and affects the outcome.
Mediators help understand the pathway through which an effect occurs.
What is causal mediation analysis?
Techniques for estimating how much of the effect of a treatment on an outcome results from the treatment’s effect on a mediator and the mediator’s effect on the outcome.
This analysis is crucial for understanding the underlying mechanisms of observed effects.
What was the primary goal of the experiment involving housing vouchers?
To learn whether moving to a low-poverty neighborhood would be beneficial for economic, mental, and physical well-being.
What were the findings regarding physical health, mental health, and subjective well-being for households receiving a housing voucher?
Households in the treated condition experienced better physical health, mental health, and subjective well-being than those in the untreated condition.
Were there any significant differences in economic outcomes between the treated and untreated households?
No significant differences in economic outcomes were found.
True or False: The treatment of receiving a housing voucher caused improved well-being.
True
What is one possible alternative mechanism that might explain the improved well-being from receiving a housing voucher?
Increased social connections or support systems.
How could the experiment be modified to better elicit the effect of moving to a low-poverty neighborhood?
By including a control group that moves to neighborhoods with varying poverty levels.
What was the additional treatment considered in the experiment?
A group of individuals were assigned to receive a housing voucher to move anywhere they liked.
To separate the effect of moving to a low-poverty neighborhood from the effects of moving in general, what comparison should be made?
Compare outcomes of those moving to low-poverty neighborhoods with those moving to unrestricted neighborhoods.
What was the compliance rate for households using the voucher when there were no restrictions on where to move?
63 percent
What was the compliance rate for households using the voucher when it required moving to a low-poverty neighborhood?
48 percent
What complication arose due to noncompliance in the experiment?
Some assigned to the voucher treatment chose not to move, and some in the unrestricted condition moved to low-poverty neighborhoods.
What is one approach to estimate the effect of moving to a low-poverty neighborhood considering the noncompliance issues?
Use instrumental variable methods to account for noncompliance.
What hypothesis is suggested about the relationship between education and political participation?
Education increases political participation due to an income or wealth mechanism.
In a regression analysis, what does a smaller coefficient for schooling indicate when income is included?
It suggests that income may explain some of the relationship between schooling and voter turnout.
True or False: Compulsory schooling requirements affect voter turnout among individuals born at the end of the calendar year.
True
What natural experiment is used to estimate that schooling significantly increases earnings?
The natural experiment involving individuals born toward the end of the calendar year.
What finding was observed regarding college degrees in engineering and political participation?
Those in higher-paid specialities participate in politics more than those in lower-paid specialities.
What is a recommended reading for learning about causal mediation analysis?
Yes, But What’s the Mechanism? (Don’t Expect an Easy Answer) by Bullock, Green, and Ha.
What study focused on reducing crime and violence through cognitive behavioral therapy in Liberia?
Reducing Crime and Violence: Experimental Evidence from Cognitive Behavioral Therapy in Liberia.
What effect does the Jackie (and Jill) Robinson Effect study explore?
Why do Congresswomen outperform Congressmen?
What is the title of the study on social pressure and voter turnout?
Social Pressure and Voter Turnout: Evidence from a Large-Scale Field Experiment.
What are some key studies on economic prosperity and conflict?
- Workers, Warriors, and Criminals: Social Conflict in General Equilibrium
- Commodity Price Shocks and Civil Conflict: Evidence from Colombia
What classic paper discusses the effects of moving to opportunity in Boston?
Moving to Opportunity in Boston: Early Results of a Randomized Mobility Experiment.
