Clarifications on Requirements and Assumptions:

[lisawym]

In ensuring a precise understanding of our analysis framework, certain requirements and assumptions need clarification.

[lisawym]

Class Note 11/14

1. Include a Minimum of Three States in the Comparison Group
When conducting a difference-for-difference analysis, it's essential to select a comparison group comprising at least three states. This is crucial because there may be unaccounted factors influencing opioid usage trends in states that we haven't considered. Pooling diverse states together helps mitigate potential external influences.

2. Thoughtful Selection and Assessment of Comparison States
The selection of comparison states is based on our understanding of the factors at play. Once identified, we assess these states to ensure that, before the policy change, they exhibit similar trends to our target states. In the final report, it's important to explicitly state the rationale behind choosing specific states for the comparison group.

3. Track Trends Over a Minimum of Three Years for Comprehensive Insights
For a comprehensive analysis, tracking trends over a minimum of three years before and three years after the policy change is necessary. Optimal analysis may extend to 3-5 years to capture a clear picture of the policy's impact.

4. Consider Monthly Changes for Specific Analyses
Monthly changes aren't crucial for most analyses, except in the case of Texas's prescription analysis, where only one year of data is available. In this specific instance, tracking monthly changes can be pursued for additional insights.

5. Standardize Treatment of the Policy Change Year
It's noteworthy that all policy changes occur at the beginning of a year, typically in February. Consequently, we treat the year of the policy change as the post-policy period. This standardized approach allows for consistent analysis across different states and policies.

[lisawym]

What is the scope of drug overdose death?
"Drug poisonings (overdose) Unintentional (X40-X44)", "Drug poisonings (overdose) Suicide (X60-X64)", "Drug poisonings (overdose) Undetermined (Y10-Y14)", "All other drug-induced causes",
is "All other drug-induced causes" also considered as drug overdose death?