Ch3 - Empirical Methods in Corporate Governance Research Flashcards
Endogeneity
- Arises when explanatory variables are correlated with the error term in a regression model
- This correlation leads to biased and inconsistent parameter estimates
Sources of Endogeneity
- Omitted Variables
- Reverse Causation
- Measurement Errors
- Signaling Effects
Reverse Causation
- direction of causality between variables is unclear.
- change in one variable causes a change in another or if the relationship is bidirectional (-> Egg Chicken)
Measurement Errors
- Discrepancies between the true values of variables and their measured ones
- Especially for proxy variables
Signaling Effects
These occur when actions taken by firms or individuals convey information to stakeholders (bad signal when firing CG officer)
Addressing Endogeneity
- Advanced Econometric Techniques (two-stage least squares (2SLS))
- Smart Empirical Design (randomized trials)
- Natural Experiments (exogenous shocks)
- Improved Data and Proxy Variables (better data sources)
Randomized trials (RTs)
- gold standard
- treatment and control
Randomized Experiments vs Endogeneity
– reverse causation and simultaneity (only the input variable is changed),
– omitted variables (all controls are orthogonal to the shock),
– measurement errors in the covariates (all controls are independent of the
shock),
– signaling effects (the shock is exogenous).
Natural Experiments
exploit exogenous shocks as treatments to assess causal relationships (e.g. regulatory changes) for comparing outcomes before and after the shock
Difference-in-differences (DID) designs
compares changes in the variable of interest between treatment and control groups over time (natural experiments)
Why are Natural Experiments and DID difficult for CG-Research?
It’s not possible to have to variants of markets running at the same time
Regression discontinuity designs (RDD)
Leverage a threshold that determines treatment assignment. Entities above the threshold receive treatment, while those below do not.
-> RDD regressions utilize a dummy variable indicating treatment status and interactions between the forcing variable and the treatment dummy
Sharp RDD
Treatment assignment is deterministic based on the forcing variable. Knowing the forcing variable’s value definitively determines treatment status
Fuzzy RDD
The probability of treatment assignment changes discontinuously at the threshold. While the forcing variable influences treatment assignment, there is not a perfect one-to-one relationship