很多市场环境下，厂商针对消费者寻求多样化购买采取预先承诺定价的营销策略。本文建立两期动态博弈模型，研究消费者寻求多样化购买对厂商预先承诺定价行为和市场绩效的影响。研究结果表明：（1）在预先承诺定价机制下，厂商通过预先承诺定价向老顾客收取低价，向新顾客索取高价；（2）消费者寻求多样化购买弱化了厂商间的竞争，导致"默契合谋"；（3）与其他定价机制相比，预先承诺定价机制提升了消费者剩余，降低了厂商利润和社会总福利。本文的研究结果很好地解释了现实经济中许多厂商的定价策略行为，对其产品营销战略具有重要指导意义。

One can easily observe in the real life that consumers intend to be variety-seeking in many markets. For instance, in the restaurant industry, people want to go to different restaurants for various food. In the tourist industry, consumers wouldn't like to go to the same scenery spot twice because they may feel aesthetic fatigue. These phenomena also exist in the fashion industry, in which the clients pay more attention to the product experience. In these markets, people who consume the same product twice may suffer from a utility loss. This kind of loss refers to the "staying cost". Moreover, one can also observe that some firms often tend to pre-commit lower prices for regular customers by offering membership card or discount coupons in these markets. In this paper, we analyze the marketing strategy made by firms in these markets as well as the effect of this behavior on the social welfare.
We develop a two period duopoly model based on Hotelling framework. We consider the case that firms can pre-commit special second period prices for loyal consumers. Both firms simultaneously set price as well as pre-commitments in the first period.In the second period, firms announce second period prices. At this time, loyal consumers can pay pre-commitment price, while newcomers must pay the second period price.
In the first part, we develop a two stage model and solve the sub-game perfect Nash equilibrium. The equilibrium shows that:(1) under the pre-commitment pricing scheme, firms can offer pre-commitment prices to the repeat purchasing consumers, and charge higher prices to the new ones; (2) the behavior of consumers' variety-seeking will weaken competition between firms, which lead to "tacit collusion".
In the second part, we make welfare analysis for the equilibrium outcome. We calculate the consumer surplus, firm profits and social welfare. We find that compared with other pricing schemes, pre-commitment pricing reduces profits of firms and social welfare, but increases consumer surplus.
In order to make our results more intuitive, we assign values to some variables to implement a numerical analysis. We offer the effect of staying cost on equilibrium in a coordinate system. We also assign different values to the staying cost so as to observe the difference between pricing strategies.
In summary, our model can make a good interpretation for some economic phenomena and enterprises' strategic behaviors in the real economy, and further make some significant suggestions for the firms' marketing strategy.