中文摘要：

通过Hotelling模型对PC软件产品竞争性升级进行了研究，重点分析了网络外部性、转换成本、升级产品质量（或功能）的提高对升级定价及其竞争策略的影响．主要成果包括以下几个方面（1）在消费者静态预期的条件下，网络规模大的厂商总是偏好不兼容，网络规模小的厂商偏好全兼容．（2）分析了影响版本升级价格、竞争性价格和全价的相关因素．（3）解释了转换成本和实施竞争性升级的关系．（4）分析了厂商夺取竞争对手厂商客户的条件以及争夺新客户的竞争策略．对厂商的竞争性升级定价具有重要的理论指导意义．

英文摘要：

We studied the PC software upgrade competition with Hotelling model. It shows that the upgrade pricing is affected by network externality, switch cost, and the quality of upgrade product. Many conclusions were drawn： （1） if users have rational expectations, the firm with larger net scale always prefers incompatibility, the finn with smaller net scale always prefers full compatibility; （2） the relevant factors are analyzed which affect version upgrade price, competitive price and full price; （3） the relationship between switch cost and competitive upgrade is explained; （4） the conditions are analyzed in which a firm can attract the rival＇s customers and analyze the strategies by which a firm can attract new customers. This paper is of theoretical importance for firms to make decision on competitive upgrade pricing.