Three Essays on the Technology Market, Technology Gap across Countries and Innovation

This thesis consists of three chapters on innovation and economic growth, especially on technology market frictions and technology gap across countries.Chapter 1 is a theoretical model to quantify frictions in technology market. I build a firm dynamics model with firm in-house R&D and patent market and conceptually include three types of frictions in technology market. First is the search cost of finding a patent in the market. Basically, if the search cost is high, the firm will do less search, and it will lower the meeting rate between potential buyers and sellers. Second is the fixed transaction cost, it will impede the trade of low-quality patents because they cannot bring enough high benefits. Third is the information asymmetry on patent quality, conceptually, it is the share the patent that the firm meet but cannot tell the true quality of it. Let assume a very extreme case, that for all the patents that you meet, you cannot know the true quality of it, so at this time, all the buyers are only willing to pay the same price for all of the patents, and high-quality patent cannot get the price it deserves, they will exit this market.Chapter 2 first documents several novel stylized facts from Chinese patent transaction data matched with manufacturing firm data. A key finding is that Chinese patent market is significantly less developed than the U.S. I structurally estimate the theoretical model in Chapter 1 and find the following two main results. First, Chinese patent market plays a small role in growth. It only accounts for 5% percent of China's GDP growth rate, as opposed to 17% in the U.S. Second, I evaluate the importance of three frictions calibrated to Chinese patent market: search cost, fixed transaction cost and information asymmetry. Search cost turns out to be the main friction to explain the gap of patent market size. If search cost was reduced to the US level, China's productivity growth would increase by 0.16 percentage points.Chapter 3 is a joint work with Hanming Fang, Zheng (Michael) Song and Hanyi Tao. We construct various quality measures to investigate the evolution of the quality of granted Chinese patents, relative to that of the US patents, over the period of 1985 and 2020. Three novel measurements of patent quality for cross-country comparison are developed in this paper: the forward citations standardized by dual-listed patents, the technology gap based on new words, and the cross-country knowledge transfer. All the measures gives consistent results that although there exists technology gap between China and U.S., the gap between these two countries is narrowing sharply, especially in the industry like Chemistry.这篇论文关注于创新和经济增长，尤其是技术市场摩擦和跨国间的技术差距。第一章节是一个旨在量化技术市场摩擦的理论模型。在这个企业动态模型中，企业可以通过自主创新或者去技术市场购买其他企业成功的创新发明来提高自身的生产率。在技术市场中我考虑了三种摩擦。第一个是搜寻成本，如果在技术市场中，搜寻企业所需要的专利需要花费大量成本，这直接会降低潜在买方进行搜寻的努力，从而降低潜在买卖双方见面的机会。第二个摩擦是固定的交易费用，它会阻碍低质量专利的交易，因为低质量专利不能给潜在买家带来足够的利润。最后，我还考虑了专利质量在买卖双方的信息不对称，我以当潜在买家在市场上遇到一个专利能正确判断出其真实质量的概率来模型化。让我们假设一个非常极端的情况，如果没有买家能判断出专利的真实质量，那么所有买家都只愿意付出一个期望价格，所以高质量专利得不到其应得的价格，所以信息不对称会减小高质量专利所有者进入到市场进行专利交易的激励。第二章中，我首先应用中国专利市场数据匹配工业企业数据，一个重要的发现是中国专利市场的发展程度远远低于美国。随后，我运用第一章节的理论模型，结合现实数据加以参数估计，有以下两点结论：（1）中国专利市场在经济增长中起到的作用远小于美国，大约只能解释经济增长的5%，而美国是17%；（2）我发现搜寻成本是阻碍中国专利市场发展最重要的摩擦，如果中国的搜寻成本参数可以下降到美国的水平，那么中国的经济增长率可以提高0.16个百分点。第三章是一篇和方汉明，宋铮以及陶涵毅合作的论文，在这个章节，我们构建了三种新的衡量跨国间技术差距的度量，来对比中国专利和美国专利的质量差距及这个差距的年份变化。这三个度量分别是：（1）基于专利被引用量的度量--我们用在两国都有注册的跨国专利对专利引用量进行标准化；（2）基于新词学习的度量；（3）跨国间的知识流动。这三种度量结果都稳健地发现中美之间存在技术差距，但这个差距在逐渐缩小，尤其在某些行业，比如化学行业。ZHANG, Yiran.Ph.D. Chinese University of Hong Kong 2021.Includes bibliographical references (leaves )Abstracts in English and Chinese.Title from PDF title page (viewed on ...