Branded pharmaceutical manufacturers frequently offer "copay coupons" that insulate consumers from cost-sharing, thereby undermining insurers' ability to influence drug utilization. We study the impact of copay coupons on branded drugs first facing generic entry between 2007 and 2010. To overcome endogeneity concerns, we exploit cross-state and cross-consumer variation in coupon legality. We find that coupons increase branded sales by 60+ percent, entirely by reducing the sales of bioequivalent generics. During the five years following generic entry, we estimate that coupons increase total spending by $30 to $120 million per drug, or $700 million to $2.7 billion for our sample alone.

中文翻译：

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当折扣提高成本时：共付额优惠券对一般使用的影响

品牌药品制造商经常提供“共付优惠券”，使消费者免于分摊费用，从而削弱保险公司影响药物使用的能力。我们研究了自付费优惠券对 2007 年至 2010 年首次面临仿制药进入的品牌药物的影响。为了克服内生性问题，我们利用优惠券合法性的跨州和跨消费者差异。我们发现优惠券将品牌销售额提高了 60% 以上，这完全是通过减少生物等效仿制药的销售额。在仿制药进入后的五年内，我们估计优惠券使每种药物的总支出增加了 30 至 1.2 亿美元，仅我们的样本就增加了 7 亿至 27 亿美元。