风险投资介入与企业创新：基于PSM模型的经验证据

“大众创业、万众创新”背景下，研究风险投资介入对企业创新绩效的影响具有重要理论与现实意义。以2010-2017年创业板公司为样本，采用倾向得分匹配法（PSM）模型,实证分析风险投资介入对企业创新绩效的影响,发现风险投资介入显著促进专利申请量，且对发明专利申请量和实用新型专利申请量有显著正向作用，而对外观设计专利影响并不显著。进一步考察不同背景和投资策略的风险投资对创新绩效的潜在影响，结果显示：与单独投资相比，联合投资对专利总申请量和发明专利申请量增加的促进作用更显著；与私营风险投资和外资风险投资相比，国有风险投资具有更强的发明取向和更长的投资时间，能显著促进发明专利等创新绩效提升，而私营和外资风险投资对公司创新绩效的影响不显著。     

Research and development and trade policies for product innovation in the presence of foreign competition

This paper examines two policy instruments — a matching grant and import tariffs — for encouraging research and development (R&D) in product innovation by a domestic firm when it faces foreign competition. We do so by developing a theoretical model of product innovation where R&D effort is endogenous and its outcome uncertain. We examine the effects of a reduction in import tariffs on private expenditure on R&D, on public support for such R&D, and on total R&D expenditure. We find that in response to a reduction in import tariffs, the domestic firm always reduces its private R&D investments, but the total level of R&D expenditure (i.e., including public support) might go up depending on the level of tariffs. In particular, we find that it will go up if the initial level of tariff is higher than a critical level. When tariff is endogenous, we find that the socially optimal level of tariffs is positive. One finding that is of particular interest is that supporting private attempts to product innovate in the form of a matching grant program leads to a socially optimal level of product R&D.     

Public university orientation for high-school students. A quasi-experimental assessment of the efficiency gains from nudging better career choices

We adopt a quasi-experimental approach to measure the causal effect, on first-year students in bachelor-level courses at the Department of Economics and Business Studies of the University of Genoa, Italy, of having been treated to a recently activated orientation program when they were high school seniors. Improvements are evaluated at the end of the first academic year in terms of grade point average (GPA), inactivity (failing to pass even a single exam) and number of successfully completed exams. Treatment effects on GPA are estimated both for the overall treatment group and for subsamples consisting of treated students with high and with low high school exit grades. After performing several sensitivity checks, a sizeable treatment effect is confirmed both in terms of inactivity and in terms of average GPA. No clear effect was found on the number of exams. Effects on GPA are considerably stronger on students with lower high school exit grades.     

人才头衔能否提升科技人才职业成就动机——来自我国一流大学建设高校的证据

职业成就动机是提升个体创新能力和促进创新行为的核心要素，由国家各类人才资助计划催生的人才头衔能否进一步激励科技人才创新备受关注。依据成就动机理论和综合激励理论，建立人才头衔、职业成就动机与创新成果产出关系理论模型，采用倾向得分匹配方法，对14所一流大学建设高校的抽样调查数据进行分析，验证人才头衔与职业成就动机的关系。研究发现，我国一流大学建设高校科技人才的成就动机普遍较高，人才头衔对科技人才成就取向、努力取向、专业充实取向和社会责任取向维度的职业成就动机具有显著提升作用。最后，提出完善国家人才资助计划体系、处理人才头衔与人才考核关系、发挥人才头衔对科技人才的正向激励作用等对策建议。     

供给侧生产端变化对中国粮食安全的影响研究

在“谷物基本自给、口粮绝对安全”的粮食安全战略背景下,粮食供给侧生产端对于保障中国粮食安全起到关键性作用。近年来,随着城镇化和农业现代化的推进,新型农业经营主体和土地规模化经营快速发展,粮食生产在质量效益和专业化水平不断提高的同时,其土地生产效率的提高和市场风险的防范面临挑战;粮食生产成本的攀升和比较收益的下降,使农业支持家庭生计的功能不断弱化,导致农户种粮意愿普遍降低;居民食物消费结构升级引致种植结构调整,使保障口粮绝对安全的政策成本上升。粮食生产主体结构与行为、生产成本与比较收益、供需匹配关系等生产端的重要变化,对粮食供给能力进而对国家粮食安全产生重要影响。为此,需要优化粮食安全目标,合理协调“保产量”与“优结构”的关系;完善价格激励机制,以需求升级为导向优化生产结构;优化收储调控机制,增强粮食安全风险应对能力;多举措提高农户种粮和地方政府发展粮食的积极性的同时充分利用国外资源和国际市场。     

Matching with externalities: The role of prudence and social connectedness in stability

In matching problems with externalities, prudence measures the importance an agent gives to others’ potential reactions when she considers deviating and social connectedness measures others’ capacity to react to the agent’s deviation. Assuming that externalities and preferences are random, the roles of prudence and social connectedness are studied. It is shown that asymptotic stability – a property that never holds in the absence of externalities – is achieved when the product of social connectedness and prudence grows at least exponentially with the population. Since social connectedness increases quickly in both the marriage and roommates markets, stability obtains even when prudence vanishes (sufficiently slowly).     

在低维空间实现的基于MP的图像稀疏分解

研究利用Matching Pursuit(MP)方法实现的图像稀疏分解算法，针对其中关键难题，提出利用在低维空间的搜索实现高维空间的搜索的快速方法。算法的有效性为实验结果所证实。     

Job and vacancy competition in empirical matching functions

We investigate job competition among job seekers and vacancy competition among firms extending the job competition model proposed by Anderson and Burgess (Anderson, P.M., Burgess, S.M., 2000. Empirical matching functions: Estimation and interpretation using state level data. Review of Economics and Statistics 82, p. 90–102). Our results for data from West Germany provide evidence for both phenomena, thereby extending and qualifying previous insights.     

锻炼习惯能带来更高的收入吗?

在中国城乡居民体育锻炼现状不容乐观以及居民收入水平增速不断放缓的背景下,劳动力市场中锻炼的收入效应值得深入研究。文章基于2014-2016年中国劳动力动态调查数据,使用固定效应模型、工具变量以及倾向性匹配得分方法估计个体的锻炼行为对收入水平的影响,并探讨可能的作用机制。研究结果表明,锻炼确实能够为个体带来显著的收入溢价,同时各种稳健性检验也证明了研究结论的可靠性。机制分析结果表明,锻炼行为会通过影响个体的健康水平、外貌状况以及对待工作的态度,从而影响个体的收入水平。异质性分析结果表明,年龄上,锻炼对个体收入的影响主要存在于青年阶段和中年阶段,且青年阶段的作用机制主要是外貌状况,而中年阶段的作用机制主要是健康水平;教育程度上,锻炼对收入的影响主要存在于中等教育程度的个体。本研究的结论表明,政府应当采取各种措施鼓励居民参与到体育锻炼中来,尤其是应当将中青年群体和中等教育群体吸引进来,这对于解决当前如何进一步提高居民收入水平的困境可以说是另辟蹊径。