藥品需求的品牌忠誠與學習效果

Brand Loyalty and Learning in Pharmaceutical Demand

慢性病藥品，例如高膽固醇、心臟病、糖尿病用藥，需要長期反覆服用。因此，消費者動態行為在此類藥品需求扮演重要角色。本文使用美國膽固醇用藥市場資料，估計包含品牌忠誠與學習效果的需求模型。估計結果顯示，在此市場中，藥品分子層級的轉換成本極高，學習效果也很強。高轉換成本增加連續選擇同一藥品的機率，學習效果則提高病患長期對一藥品分子的依賴程度。作者討論這些估計結果，對於藥廠、保險公司，以及醫療政策制訂者的意涵。

Medicines for chronic conditions like high cholesterol, heart disease, and diabetes are repeatedly used for a long period of time. Consumer dynamics thus plays an important role in the demand for those drugs. The paper estimates a demand model with brand loyalty and learning, using data from cholesterol-lowering drug markets in the United States. The estimates suggest high switching costs and strong learning effects at the molecule level in the markets. Switching costs raise the predicted probability of choosing the same drugs successively, and learning greatly increases patient stickiness to a molecule in the long run. I discuss implications of the estimated state-dependent effects for drug manufacturers, insurance companies, and healthcare policy makers.