中文摘要：

工艺创新和产品创新是企业技术创新的主要模式，不同创新模式下企业研发投入决策与作为买方的下游行业市场势力有关．本文通过构建纳入上下游企业的三阶段研发决策模型，考察了买方势力对上游企业工艺创新和产品创新的异质性影响，得到以下结论：买方市场势力越强（企业数越少），上游企业的工艺创新投入强度越小，而产品创新投入强度越大；卖方市场势力与本行业企业的产品创新正相关，与工艺创新的关系不确定；买方技术能力的提升能够通过产业间传导机制增强上游企业的产品创新激励，对工艺创新则存在负效应．进而，以我国制造业大中型企业的统计数据为样本对模型所得结论进行了实证检验，回归结果与理论预期基本一致，其中交互作用项的参数估计表明，买方势力对上游企业创新投入的作用依赖于卖方市场势力的条件效应．

英文摘要：

Process innovation and product innovation are the main modes of firm＇ s technological innovation. R＆D decisions under different modes depend on buyers＇ power. A three-stage R＆D decision-making model is built including upstream and downstream firms to study the heterogeneity influence of buyers＇ power on process innovation and product innovation of upstream firms. The results show that the stronger the buyers＇ power, the less the investment intensity of process innovation and the more the product innovation intensity of the upstream firms. The market power of sellers is positively correlated with product innovation in their indus- try, while the relation with process innovation is uncertain. Buyers＇ technological capabilities have a positive impact on product innovation through inter-industry transmission mechanism and have a negative impact on process innovation. The large and middle-sized enterprises in Chinese manufacturing industry are tested empir- ically. Consistent with the theoretical hypotheses, the parameter estimation of interaction term shows that the effect of buyers＇ power on the upstream enterprise innovation input depends on the seller＇ s market power.