<p>Selected major pharmaceutical policy events.</p>

Medium-frequency CARs were generally negative for both centralized procurement events, but centralized drug procurement showed broader negative accumulation across sub-sectors, whereas centralized procurement of high-value medical consumables showed greater sectoral differentiation. Although the clinical trial data self-inspection and verification event and the reform of the drug review and approval system both involved drug R&D and registration regulation, their abnormal-return patterns differed markedly, with the latter showing broadly positive medium-frequency CARs.

The aggregate industry index may not fully capture underlying differences when sub-sector responses diverge substantially, and high- and medium-frequency CARs also differ in direction for some events and sub-sectors. In addition, the cumulative direction of CARs over wider event windows may differ from the trajectory of daily ARs following the policy announcement. Overall, generalizations based on policy categories, an aggregate industry index, or a single event window may overlook important differences in abnormal returns across industry-index levels, return scales, and temporal paths.</p></div>