12月12日 上午 腾讯会议（ID：651-887-607）
主持人：张萃 教授 暨南大学经济学院国际经济与贸易系副主任
Interregional Accessibility and Firm Creation in the Fragmented Economy
主持人：罗唯 助理教授 暨南大学经济学院经济系
Bias and Sensitivity under Ambiguity
Mapping U.S.-China Technology Decoupling: Policies,Innovation and Firm
12月12日 下午 腾讯会议（ID：130-152-778）
主持人：上官若 助理教授 暨南大学经济学院国际经济与贸易系
Losing Market Dominance in a Growing Industry:BYD Company and Electric
Vehicles in China
Air Pollution and Entrepreneurship
Tying and Platform Competition in the Food Delivery Market
The Management of Knowledge Work
题目1：Interregional Accessibility and Firm Creation in the Fragmented Economy
Does the reduction in international travel time lower the entry cost for firms, especially those accessing non-local suppliers in the globally fragmented economy? I study this question in the context of recent US-China aviation network expansions, documenting sharp and unevenly distributed travel time reductions between US cities and Chinese prefectures.
Employing a novel instrument for travel time constructed from the gradual deregulation of the US-China flight market, I show that the reduction in travel time to China promotes the creation of firms in US cities, more in industries that use many different suppliers. To account for the heterogeneity in supplier presence within China, I estimate a quantitative spatial model featuring sourcing location choice, input-output structure, and a firm entry decision.
The model illuminates that the 2004-2013 US-China aviation network expansion increases US firm creation by 1.7%. The heterogeneity in supplier presence across Chinese prefectures drives 42% of the increase because of assortative matching between supplier presence and time reductions in the sparse US-China flight network.
题目2：Bias and Sensitivity under Ambiguity
This paper characterizes the effects of smooth ambiguity under imperfect information: from a Bayesian perspective, it amounts to additional sensitivity to signals and a pessimistic bias.
This characterization takes a particularly simple form in a general environment that allows for dynamic information and general equilibrium consideration, and it provides a tractable computational method and permits comparative statics analysis.
On the applied side, we show that ambiguity aversion helps rationalize the empirical distribution of inflation forecast bias and persistence conditional on households’income. We also show that when facing the trade-off between inflation and unemployment à la Barro-Gordon (1983), creating certain ambiguity by the policy maker can improve welfare.
题目4：Mapping U.S.-China Technology Decoupling: Policies, Innovation, and Firm Performance
We develop measures for technology decoupling and dependence between the U.S. and China based on combined patent data.
The first two decades of the century witnessed a steady increase in technology integration (or less decoupling), but China’s dependence on the U.S. increased (decreased) during the first (second) decade.
Firms covered by China’s Strategic Emerging Industries policies became less decoupled with the U.S., gained cash flows and valuation but saw no improvement in either innovation output/quality or productivity. Post U.S. sanctions, firms in sanctioned sectors and their downstream suffer in performance but also became less decoupled with the U.S. However, firms in the upstream of the sanctioned sectors experienced significant improvements in productivity and produced more innovation of breaking-through and explorative quality.
题目5：Losing Market Dominance in a Growing Industry:BYD Company and Electric Vehicles in China
Using rich data from a major Chinese city, we find a large and persistent decline in the market share of BYD Company in the Electric Vehicle (EV) market: from above 95% in 2014 to close to 10% in 2020. We study the contribution to this dramatic decline of strategic decisions on prices and product characteristics by BYD and its competitors in a changing environment characterized by growing demand, rapid technological progress, disruptive market entry, and frequent changes in government subsidies to EVs.
Our results are based on the estimation of a structural model of demand and price competition in an oligopoly differentiated product industry, and on a large set of counterfactual experiments that identify the contribution of different factors to the observed decline. We find that most of the decline in BYD’s market share can be explained by product proliferation and product design from early competitors like Tesla and Porsche: their brand names and product designs generated substantial business stealing from BYD.
A second important factor was the rapid technological improvement in the industry during this period that made BYD to lose its initial cost advantage. Market entry from startups played a much smaller role in the decline on BYD’s market share. Despite the decline in its market share, BYD increased its average price cost margin during this period, from 12% in 2014 to 45% in 2020.
Our counterfactuals show that the decline in BYD’s market share and the increase in its markup are both closely related to changes in product design by BYD and its competitors. As a response to increasing competition, BYD’s strategy was to concentrate in higher quality products, with lower market share but larger margins.
题目6：Air Pollution and Entrepreneurship
We examine the causal effect of air pollution on an individual’s propensity for entrepreneurship in China. Our preferred model, which employs an instrumental variable approach to address endogeneity arising from sorting into entrepreneurship and locational choices, suggests that exposure to higher intensity of air pollution lowers one’s proclivity for entrepreneurship.
We also find that industrial activity and self-efficacy mediate the relationship between air pollution and entrepreneurship. In addition, education and gender further moderate the relationship between air pollution and self-efficacy. In particular, air pollution negatively affects self-efficacy among the less-educated and females.
题目7：Tying and Platform Competition in the Food Delivery Market
Platforms offering multiple products may take advantage of their market power on one side of the market and force the other side to accept tied products. Such behaviors can generate unfavorable consequences for market participants and deter potential entrants that provide similar services.
We examine the phenomenon by studying Hong Kong's food delivery market, where restaurants seeking delivery services are also required to procure pickup services from delivery platforms.
Using orders from two major food delivery providers, we estimate consumers' demand for the two types of services. We then conduct counterfactual analyses to study the impact of service typing on restaurants' welfare.
题目8：The Management of Knowledge Work
We explore the role of management in knowledge-intensive work. Our theory posits that the function of the manager mainly consists of (i) ex ante coordination in terms of specifying and delegating tasks to her team and (ii) ex post coordination of the team’s execution of those tasks as unexpected events unfold.
Consistent with the predictions generated from this view, and using microlevel data from architectural design teams, we find that the manager’s involvement in a project is high in the beginning but decreases as the project progresses. However, when the manager has better ex ante information, she decreases her involvement ex ante.
We also find a higher workload of the manager not only strains her involvement but also the team's time spent on the project. Our analysis on workload shows that the manager and the team synchronize their involvement in proportion under shifting workloads.
Finally, both over- and under- involvement by the manager from our predicted involvement correlates with higher team hours and hence lower profitability. Our study highlights the importance of managerial coordination and rational inattention in organizing knowledge workers in modern economies.