What you will learn
- Multiple horizons
- Overlapping samples
- Alternative explanations
- Net-of-cost implementation limits
Multiple horizons
Multiple horizons and subgroups increase the search space. Report the full analysis plan and distinguish primary tests from exploratory comparisons. An attractive subgroup discovered after inspection needs new evidence.
Overlapping samples
Overlapping windows can reuse the same market movement across events or observations. This creates dependence and can overstate precision if treated as independent data. Identify overlap explicitly.
Alternative explanations
Alternative explanations include simultaneous news, changing expectations and general liquidity conditions. An event-associated response does not uniquely identify a causal channel without stronger design assumptions.
Net-of-cost implementation limits
Translate any research finding into an implementation test separately. Include signal availability, order delay, spread and risk. A statistically clear historical reaction may still be too small, too fast or too costly to exploit.
Worked example
Two announcements occur minutes apart and their response windows overlap. Assigning the full move to each and treating the observations as independent double-counts shared information.
Try it yourself
Explain how to report this overlap and what conclusions should remain limited.
Show the worked solution
Flag overlapping events, use an appropriate grouping or exclusion rule defined in advance, and assess dependence. State that attribution to a single release may remain unresolved even if the joint window shows a clear move.
Apply this to your course project
Submit a preregistered event-study protocol and a reproducible worked sample.
Keep the calculation inputs, assumptions and decisions with your work. Practical exercises are self-reviewed; the scored knowledge checks assess the questions shown, not an independent certification of practical competence.