We present a review of Gerald Goodhardt's most famous contribution to marketing science—the NBD-Dirichlet model. This provides a powerful illustration of the complex pathway and useful associated discoveries that over 25 years lead to the specification and application of a key marketing model. We identify the process that started with the negative binomial distribution (NBD) applied to purchase incidence, examined alternatives such as the logarithmic series distribution (LSD) and the beta binomial distribution (BBD), and along the way developed conditional trend analysis (CTA). We then explore the development of brand choice beginning with duplication of purchase as a method for understanding the underlying patterns, before moving into various approaches to modelling choice including a multivariate NBD, and eventually a multivariate BBD—the Dirichlet multinomial distribution (DMD). We discuss key events in modelling consumer behaviour and outline the model's implications for how marketers should think about consumers, or more specifically the Dirichlet consumer. Finally, we provide a survey of the model's applications uncovering a rich recent history and bright future for Goodhardt's legacy.

中文翻译：

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营销中的狄利克雷模型

我们回顾了 Gerald Goodhardt 对营销科学最著名的贡献——NBD-Dirichlet 模型。这有力地说明了 25 年来导致关键营销模型规范和应用的复杂途径和有用的相关发现。我们确定了从应用于购买发生率的负二项分布 (NBD) 开始的过程，检查了对数序列分布 (LSD) 和贝塔二项分布 (BBD) 等替代方案，并在此过程中开发了条件趋势分析 (CTA) . 然后，我们从重复购买开始探索品牌选择的发展，作为理解潜在模式的一种方法，然后再进入各种建模选择的方法，包括多元 NBD，最后是多元 BBD——狄利克雷多项式分布 (DMD)。我们讨论了消费者行为建模中的关键事件，并概述了该模型对营销人员应该如何考虑消费者，或者更具体地说是 Dirichlet 消费者的影响。最后，我们对该模型的应用进行了调查，揭示了古德哈特遗产的丰富近期历史和光明未来。