本期是FEC编委、密歇根州立大学经济系赵金华教授组织的环境经济学前沿专辑，将于2021年6月正式上线~

Frontiers of Economics in China

Special Issue on the Frontiers of Environmental Economics

FEC环境经济学前沿专辑

Jinhua Zhao, John M. Kerr, Maria Knight Lapinski, Robert Shupp

Reciprocity and Social Norms: Short- and Long-Run Crowding Out Effects of Financial Incentives

互惠与社会规范：财务激励的短期和长期挤出效应

https://doi.org/10.3868/s060-013-021-0009-6

Abstract: We link the reciprocity model of Falk and Fischbacher (Games and Economic Behavior 2006) with the theory of normative social behavior to study how financial incentives crowd out intrinsic motivation in both the short and long runs. Using data from a lab-based repeated public goods game, we find strong evidence in support of the reciprocity model and crowding out effects both when the payment is in place and after it stops. When the payment program is in place, subjects become less sensitive to reciprocity, perceive less kindness in others’ contributions, and care less about others’ welfare. The overall decrease in motivation to reciprocate reduces the effectiveness of the payment program by almost 50%. About 20% of the crowding out effect persists after the payment stops, and the reciprocity mechanism explains over three quarters of the long-run crowding out effect.

摘要：我们将Falk和Fischbacher的互惠模型(Games and Economic Behavior 2006)和规范性社会行为理论相结合来探析财务激励如何在短期和长期挤出内在动机。使用基于实验室的公共品重复博弈数据，我们在财务激励存在及财务激励取消后，都发现了支撑互惠模型与挤出效应的有力证据。存在财务激励时，实验对象对于互惠性的敏感度更低，对于他人捐赠感到更少善意，且更少关心他人福利。互惠动机的整体减弱将财务激励的有效性降低了约50%。财务激励取消后，约20%的挤出效应依然存在，且互惠机制可解释长期挤出效应的四分之三强。

Margaret Insley, Tracy Snoddon, Peter A. Forsyth

Strategic Interactions and Uncertainty in Decisions to Curb Greenhouse Gas Emissions

控制温室气体排放决策中的策略性互动和不确定性

https://doi.org/10.3868/s060-013-021-0010-0

Abstract：This paper examines the strategic interactions of two large regions making choices about greenhouse gas emissions in the face of rising global temperatures. Three central features are highlighted: uncertainty, the incentive for free riding, and asymmetric characteristics of decision makers. Optimal decisions are modelled in a fully dynamic, feedback Stackelberg pollution game. Global average temperature is modelled as a mean reverting stochastic process. A numerical solution of a coupled system of Hamilton Jacobi-Bellman equations is implemented and the probability distribution of outcomes is illustrated with Monte Carlo simulation. When players are identical, the outcome of the game is much worse than the social planner’s outcome. An increase in temperature volatility reduces player utility, making cooperative action through a social planner more urgent. Asymmetric damages or asymmetric preferences for emissions reductions are shown to have important effects on the strategic interactions of players.

摘要：本文考察了在全球气温上升之际两个较大地区在就温室气体排放进行决策时的策略性互动情况。本文强调了三个主要特征：不确定性、搭便车的动机、决策制定者的非对称性。本文采用一个完全动态反馈的斯塔克伯格模型来分析地区的最优决策行为。全球平均气温在模型中被设为一个均值回复随机过程。我们对HamiltonJacobi-Bellman方程的耦合系统进行数值求解，并通过蒙特卡洛模拟得出求解结果的概率分布。当参与者在各方面完全相同时，博弈结果要远劣于社会最优结果。温度波动的增加会降低参与者效用，使得通过社会合作达到社会最优的需求更为必要。本文还表明，不对称损害或对减排的不对称偏好会对参与者的策略性互动有重要影响。

Jude Bayham, Gerardo Chowell, Eli P. Fenichel, Nicolai V. Kuminoff

Time Reallocation and the Cost and Benefit of School Closures during an Epidemic

流行病期间公众时间调整行为与学校停课的成本效益分析

https://doi.org/10.3868/s060-013-021-0011-7

Abstract: School closures are an important public health intervention during epidemics. Yet, the existing estimates of policy costs and benefits overlook the impact of human behavior and labor market conditions. We use an integrated assessment framework to quantify the public health benefits and the economic costs of school closures based on activity patterns derived from the American Time-Use Survey(ATUS) for a pandemic like COVID-19. We develop a policy decision framework based on marginal benefits and costs to estimate the optimal school closure duration. The results suggest that the optimal school closure depends on how people reallocate their time when schools are closed. Widespread social distancing behavior implemented early and for a long duration can delay the epidemic for years, buying time for the development of pharmaceutical interventions and yielding substantial net benefits. Conversely, school closure, with behavior targeted to adjust only to the school closure, is unlikely to provide substantial delay or sufficient net benefits to justify closing schools for pathogen control.     

摘要：流行病期间，学校停课是对公众健康的重要干预措施。然而，关于政策成本和效益的现行评估忽略了人类行为和劳动力市场情况的影响。我们基于“美国时间使用调查”（AmericanTime-Use Survey）中的个体活动模式信息，使用一个综合评估框架来量化像新冠肺炎疫情这样的流行病期间学校停课产生的公共健康效益和经济成本。我们基于边际收益和成本制定了一个政策决定框架，来估算学校的最优停课时长。结果显示，学校的最优停课时长取决于人们在学校关闭期间的时间使用再分配。 较早施行，或长期施行广泛的限制社交距离行为可以延缓流行病的传播多达数年，为干预药物的研发争取时间并带来巨大的净收益。反之，如果人们的行为仅仅为学校停课而做调整，学校停课就不太可能极大延缓流行病的传播或带来充分的净收益。在这种情况下，为病原体控制而关停学校的做法无法获得充足的支撑。

Jin Qin, Ivan Kandilov, Roger H. von Haefen

Air Pollution and Trade: the Case of China

中国视角下的大气污染与国际贸易

https://doi.org/10.3868/s060-013-021-0012-4

Abstract: We estimate the effects of trade on air pollution in China. To address endogeneity concerns, we use an instrumental variable strategy that treats the Great Recession as an exogenous shock that differentially affected China’s coastal provinces, which export a greater volume of manufacturing as they are closer to navigable waters. In our empirical analysis, we employ annual data on emissions of sulfur dioxide as well as smoke and dust at the province level from 2003 to 2015 to measure air pollution intensity (the ratio of air pollution to GDP), and we also use fine particulate matter (PM 2.5) concentrations data derived from satellite imagery as a robustness check. We find that a decrease in trade intensity (the ratio of trade to GDP) by 10 percentage points (a negative trade shock similar to what occurred during the Great Recession) increases sulfur dioxide emissions intensity by about 38 percentage points. Emissions of the other two air pollutants grow by similar proportions.   

摘要：本文意在研究国际贸易对于中国大气污染的影响。我国沿海各省具有绝佳的水运优势，因而在制造业的出口总量中占据更高比例。本研究所采用的工具变量，便是利用2008年全球金融危机对于我国不同省份出口影响的差异性，以外生冲击解决内生问题。实证分析阶段，本研究以2003至2015年间我国各个省份二氧化硫和烟尘的年度排放值来衡量空气污染烈度（空气污染之于国内生产总值的比率），并以卫星图像得到的细颗粒物（PM 2.5）浓度数据作为稳健性检测。研究发现，贸易强度（国际贸易之于国内生产总值的比重）每降低10个百分点（贸易紧缩，以模拟2008年全球金融危机），二氧化硫排放烈度将提高约38个百分点。其他两种空气污染物的排放量也会以近似比例增长。

Jerrod Penn, Wuyang Hu

Videos Improve Attention and Cheap Talkin Online Surveys

通过视频提高网络问卷调查参与者的注意力及廉价磋商效果

https://doi.org/10.3868/s060-013-021-0013-1

Abstract: Cheap Talk (CT) is a mainstay technique among stated preference practitioners to reduce Hypothetical Bias (HB). The usefulness of CT may be questionable in online surveys due to the limited control researchers have on participant engagement. In the context of an online choice experiment on hotels, we compare a control group of respondents who receive a CT script as a traditional passage of text versus a group who must answer an attention-check question to verify their comprehension of the script as well as another group who receive the CT script as a video and then answer the attention-check question. We find that compared to the control group, simply offering the attention-check question reduced WTP, and those who answer the attention-check question correctly behaved differently to those who did not. Overall, video CT script is shown to improve attention and be more effective in reducing potential HB than a text-based script.

摘要：廉价磋商（CT）是使用选择性偏好作为研究手段的科研人员常用的减少虚拟误差（HB）的手段。但在网络调查中，由于研究员对调查对象的参与注意力情况掌控有限，廉价磋商的有效性或许存疑。本文基于一个以选择实验为框架的有关酒店的网络调查，调查对象对照组得到的是由传统文本段落构成的廉价磋商信息，两个实验组之一在接收这个文本信息后必须要回答一个注意力测试问题，而另一组则会收到以视频形式展示的廉价磋商信息，之后也必须回答注意力测试问题。我们通过对比这三组调查对象来检验他们的选择行为及对廉价磋商的理解效果。经研究发现，相比对照组，仅仅提供注意力测试问题会降低调查对象的支付意愿（WTP），正确回答了注意力测试问题的调查对象与不能正确回答该问题的调查对象相比，表现出了不同的选择行为。总体上看，相比文字脚本，视频形式的廉价磋商可以提高调查对象的注意力，并能有效降低可能的虚拟误差。

Karl-Gustaf Löfgren, Chuan-Zhong Li

Envelope Theorems in Economics: Historical Development and Modern Cost-Benefit Applications

经济学中的包络定理：历史演变与现代成本效益应用

https://doi.org/10.3868/s060-013-021-0014-8

Abstract: This paper reviews some historical development and modern applications of the envelope theorems in economics from a static to a dynamic context. First, we show how the static version of the theorem surfaced in economics, which had eventually led to the well-known Shephard’s lemma in microeconomics. Second, we present its dynamic version in terms of the classical calculus of variations and optimal control theory via the optimized Hamiltonian function. Third, we show some applications of the theorem for deriving dynamic cost-benefit rules with special reference to environmental projects involving the green or comprehensive net national product (CNNP). Finally, we illustrate briefly how to extend the cost-benefit rules to a stochastic economic growth setting.

摘要：本文回顾了包络定理在经济学中从静态到动态场景下的历史演变及该定理的现代应用。首先，我们说明了该定理的静态版本如何出现在经济学中，最终引出微观经济学里众所周知的谢泼德引理。第二，我们通过经典变分学和基于优化汉密尔顿函数的最优控制理论展示了该定理的动态版本。第三，我们展示了该定理在确定动态成本效益规则方面的一些应用，特别是在涉及绿色或综合国民生产净值（CNNP）的环境项目中的应用。最后，我们简要阐述了如何把成本效益规则拓展到随机经济增长的情境。