To reliably achieve deep decarbonization of the US power sector, a candidate policy must perform robustly across a range of possible future trajectories of demand, fossil fuel prices, and prices of new wind and solar capacity. Using a modified version of the NREL ReEDS model with scenarios that span different trajectories of demand, fuel prices, and technology costs, we find that some recently proposed policies can robustly achieve 80% decarbonization (relative to 2005 emissions) or more by 2035, but many do not. The two robustly successful policies are a tradeable performance standard (TPS) and a hybrid Clean Electricity Standard (CES) with a 100% clean target, partial crediting of gas generation, and a $40/mton CO2 alternative compliance payment (ACP) backstop. Both are nearly as cost effective as the emissions-equivalent efficient policy. A $40 carbon tax nearly achieves the robust 80% threshold and, in most scenarios, drives deep decarbonization. A 90% CES (without partial crediting) fails to achieve robust 2035 decarbonization because it need not drive coal out of the system. Simply extending renewable energy tax credits, which are set to expire, does not drive significant decarbonization in most scenarios, nor does relying on increased ambition in green-leaning states.
{"title":"Robust Decarbonization of the Us Power Sector: Policy Options","authors":"J. Stock, D. Stuart","doi":"10.3386/W28677","DOIUrl":"https://doi.org/10.3386/W28677","url":null,"abstract":"To reliably achieve deep decarbonization of the US power sector, a candidate policy must perform robustly across a range of possible future trajectories of demand, fossil fuel prices, and prices of new wind and solar capacity. Using a modified version of the NREL ReEDS model with scenarios that span different trajectories of demand, fuel prices, and technology costs, we find that some recently proposed policies can robustly achieve 80% decarbonization (relative to 2005 emissions) or more by 2035, but many do not. The two robustly successful policies are a tradeable performance standard (TPS) and a hybrid Clean Electricity Standard (CES) with a 100% clean target, partial crediting of gas generation, and a $40/mton CO2 alternative compliance payment (ACP) backstop. Both are nearly as cost effective as the emissions-equivalent efficient policy. A $40 carbon tax nearly achieves the robust 80% threshold and, in most scenarios, drives deep decarbonization. A 90% CES (without partial crediting) fails to achieve robust 2035 decarbonization because it need not drive coal out of the system. Simply extending renewable energy tax credits, which are set to expire, does not drive significant decarbonization in most scenarios, nor does relying on increased ambition in green-leaning states.","PeriodicalId":19091,"journal":{"name":"NBER Working Paper Series","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83039091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
James Allen IV, Arlete Mahumane, J. Riddell, Tanya Rosenblat, Dean Yang, Hang Yu
Can informing people of high community support for social distancing encourage them to do more of it? In theory, the impact of such an intervention on social distancing is ambiguous, and depends on the relative magnitudes of free-riding and perceived-infectiousness effects. We randomly assigned a treatment providing information on true high rates of community social distancing support. We estimate impacts on social distancing, measured using a combination of self-reports and reports of others. While experts surveyed in advance expected the treatment to increase social distancing, we find that its average effect is close to zero and significantly lower than expert predictions. The treatment’s effect is heterogeneous, as predicted by theory: it decreases social distancing where current COVID-19 cases are low (where free-riding dominates), but increases it where cases are high (where the perceived-infectiousness effect dominates).
{"title":"Correcting Perceived Social Distancing Norms to Combat Covid-19","authors":"James Allen IV, Arlete Mahumane, J. Riddell, Tanya Rosenblat, Dean Yang, Hang Yu","doi":"10.3386/W28651","DOIUrl":"https://doi.org/10.3386/W28651","url":null,"abstract":"Can informing people of high community support for social distancing encourage them to do more of it? In theory, the impact of such an intervention on social distancing is ambiguous, and depends on the relative magnitudes of free-riding and perceived-infectiousness effects. We randomly assigned a treatment providing information on true high rates of community social distancing support. We estimate impacts on social distancing, measured using a combination of self-reports and reports of others. While experts surveyed in advance expected the treatment to increase social distancing, we find that its average effect is close to zero and significantly lower than expert predictions. The treatment’s effect is heterogeneous, as predicted by theory: it decreases social distancing where current COVID-19 cases are low (where free-riding dominates), but increases it where cases are high (where the perceived-infectiousness effect dominates).","PeriodicalId":19091,"journal":{"name":"NBER Working Paper Series","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75901981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Teens are risky drivers and often subject to extra restrictions. We examine the effects of an Australian intervention banning first-year drivers from carrying multiple passengers between 11:00pm and 4:59am, which had represented 3% of their accidents and 18% of their fatalities. Using daytime outcomes to account for counterfactual crash risks, we find the reform more than halves targeted crashes, casualties and deaths. The restriction also lowers crashes earlier in the evening and beyond the first year, suggesting it has broad and persistent effects on driving behavior. Overall, this targeted intervention delivers gains comparable to harsher restrictions that delay teen driving. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.
{"title":"Shaping the Habits of Teen Drivers","authors":"T. Moore, Todd Morris","doi":"10.3386/W28707","DOIUrl":"https://doi.org/10.3386/W28707","url":null,"abstract":"Teens are risky drivers and often subject to extra restrictions. We examine the effects of an Australian intervention banning first-year drivers from carrying multiple passengers between 11:00pm and 4:59am, which had represented 3% of their accidents and 18% of their fatalities. Using daytime outcomes to account for counterfactual crash risks, we find the reform more than halves targeted crashes, casualties and deaths. The restriction also lowers crashes earlier in the evening and beyond the first year, suggesting it has broad and persistent effects on driving behavior. Overall, this targeted intervention delivers gains comparable to harsher restrictions that delay teen driving. \u0000 \u0000Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.","PeriodicalId":19091,"journal":{"name":"NBER Working Paper Series","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75167483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Under majoritarian election systems, securing participation and representation of minorities remains an open problem, made salient in the US by its history of voter suppression. One remedy recommended by the courts is Cumulative Voting (CV): each voter has as many votes as open positions and can cumulate votes on as few candidates as desired. Theory predicts that CV encourages the minority to overcome obstacles to voting: although each voter is treated equally, CV increases minority's turnout relative to the majority, and the minority's share of seats won. A lab experiment based on a costly voting design strongly supports both predictions.
Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.
{"title":"Minority Turnout and Representation Under Cumulative Voting. An Experiment","authors":"A. Casella, Jeffrey J. Guo, Michelle Jiang","doi":"10.3386/W28674","DOIUrl":"https://doi.org/10.3386/W28674","url":null,"abstract":"Under majoritarian election systems, securing participation and representation of minorities remains an open problem, made salient in the US by its history of voter suppression. One remedy recommended by the courts is Cumulative Voting (CV): each voter has as many votes as open positions and can cumulate votes on as few candidates as desired. Theory predicts that CV encourages the minority to overcome obstacles to voting: although each voter is treated equally, CV increases minority's turnout relative to the majority, and the minority's share of seats won. A lab experiment based on a costly voting design strongly supports both predictions.<br><br>Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at <a href=\"http://www.nber.org/papers/w28674\" TARGET=\"_blank\">www.nber.org</a>.<br>","PeriodicalId":19091,"journal":{"name":"NBER Working Paper Series","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77381341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Lafortune, Ethan G. Lewis, J. Martínez, José Tessada
This paper estimates returns to scale for manufacturing industries around the turn of the twentieth century in the United States by exploiting an industry-city panel data for the years 1880-1930. We estimate decreasing returns to scale on average over the period, contrary to most of the existing literature, because our empirical methodology allows us to separate returns to scale from "agglomeration" effects. We also find that returns to scale grew substantially after 1910, mostly because the return to labor grew. We find that this was more marked in industries that were more intensive in human capital and energy at the beginning of the period and in cells that were less competitive. Overall, results suggest that technological change and lack of initial competition played relevant roles in the rise of larger establishments in manufacturing.
{"title":"Changing Returns to Scale in Manufacturing 1880-1930: The Rise of (Skilled) Labor?","authors":"J. Lafortune, Ethan G. Lewis, J. Martínez, José Tessada","doi":"10.3386/W28633","DOIUrl":"https://doi.org/10.3386/W28633","url":null,"abstract":"This paper estimates returns to scale for manufacturing industries around the turn of the twentieth century in the United States by exploiting an industry-city panel data for the years 1880-1930. We estimate decreasing returns to scale on average over the period, contrary to most of the existing literature, because our empirical methodology allows us to separate returns to scale from \"agglomeration\" effects. We also find that returns to scale grew substantially after 1910, mostly because the return to labor grew. We find that this was more marked in industries that were more intensive in human capital and energy at the beginning of the period and in cells that were less competitive. Overall, results suggest that technological change and lack of initial competition played relevant roles in the rise of larger establishments in manufacturing.","PeriodicalId":19091,"journal":{"name":"NBER Working Paper Series","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78783406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Domestic mobility restrictions to control the spread of COVID-19 are widespread in developing countries, and have trapped millions of migrant workers in hotspot cities. We show that bans can increase cumulative infections relative to a counterfactual sans restrictions. A SEIR model shows bans’ impacts are nonlinear in duration. We empirically test this hypothesis using a natural experiment in India as well as data from China, Indonesia, the Philippines, South Africa, and Kenya. Although very short and long restrictions limit the spread of disease, moderately lengthy restrictions substantially increase infections. This underscores the importance of considering duration in mobility-restricting policy decisions in developing countries.
{"title":"The Impact of Domestic Travel Bans on Covid-19 is Nonlinear in Their Duration","authors":"Fiona Burlig, Anant Sudarshan, Garrison Schlauch","doi":"10.3386/W28699","DOIUrl":"https://doi.org/10.3386/W28699","url":null,"abstract":"Domestic mobility restrictions to control the spread of COVID-19 are widespread in developing countries, and have trapped millions of migrant workers in hotspot cities. We show that bans can increase cumulative infections relative to a counterfactual sans restrictions. A SEIR model shows bans’ impacts are nonlinear in duration. We empirically test this hypothesis using a natural experiment in India as well as data from China, Indonesia, the Philippines, South Africa, and Kenya. Although very short and long restrictions limit the spread of disease, moderately lengthy restrictions substantially increase infections. This underscores the importance of considering duration in mobility-restricting policy decisions in developing countries.","PeriodicalId":19091,"journal":{"name":"NBER Working Paper Series","volume":"42 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80561518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subsidies to consumers may cause firms to charge higher prices, which offsets consumer benefits from subsidies. We study a subsidy program design that mitigates such price increases by making products' eligibility for a subsidy dependent on firms' commitment to price ceilings. To quantify the importance of such competition for eligibility, we develop a structural model and an estimation procedure that accommodate binding pricing constraints. We find that competition for eligibility mitigates the price increases arising from the subsidy and even leads to a reduction in prices for some products. It improves consumer and total surpluses while limiting government subsidy payments.
Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.
{"title":"The Welfare Effect of a Consumer Subsidy with Price Ceilings: The Case of Chinese Cell Phones","authors":"Ying Fan, Ge Zhang","doi":"10.3386/W28659","DOIUrl":"https://doi.org/10.3386/W28659","url":null,"abstract":"Subsidies to consumers may cause firms to charge higher prices, which offsets consumer benefits from subsidies. We study a subsidy program design that mitigates such price increases by making products' eligibility for a subsidy dependent on firms' commitment to price ceilings. To quantify the importance of such competition for eligibility, we develop a structural model and an estimation procedure that accommodate binding pricing constraints. We find that competition for eligibility mitigates the price increases arising from the subsidy and even leads to a reduction in prices for some products. It improves consumer and total surpluses while limiting government subsidy payments.<br><br>Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at <a href=\"http://www.nber.org/papers/w28659\" TARGET=\"_blank\">www.nber.org</a>.<br>","PeriodicalId":19091,"journal":{"name":"NBER Working Paper Series","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75120301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mental health problems among the elderly have attracted increasing attention. The most serious mental health problems may result in suicide, and lack of family companionship is often speculated to be a major cause. In this paper, we use high-frequency suicide rate data and utilize a novel temporal variation in the lunisolar calendar to provide evidence on the protective effects of the Chinese Lunar New Year (when the elderly people receive unusually high level of family companionship) on elderly suicide. We find that elderly suicide rate decreases by 8.7% during the Chinese Lunar New Year. In addition, the protective effects are stronger in counties where the typical level of daily family companionship for the elderly is lower. By contrast, we do not find similar protective effects for young and middle-age cohorts. We consider a variety of alternative mechanisms, and conclude that family companionship is an important channel for the protective effects of the Chinese Lunar New Year. Our study calls for greater attention to the mental health status and suicide problem of the elderly, especially with the rapid population aging and increasing prevalence of the “empty-nest” elderly in developing countries.
Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.
{"title":"Family Companionship and Elderly Suicide: Evidence from the Chinese Lunar New Year","authors":"Hanming Fang, Ziteng Lei, Liguo Lin, Peng Zhang, Maigeng Zhou","doi":"10.3386/W28566","DOIUrl":"https://doi.org/10.3386/W28566","url":null,"abstract":"Mental health problems among the elderly have attracted increasing attention. The most serious mental health problems may result in suicide, and lack of family companionship is often speculated to be a major cause. In this paper, we use high-frequency suicide rate data and utilize a novel temporal variation in the lunisolar calendar to provide evidence on the protective effects of the Chinese Lunar New Year (when the elderly people receive unusually high level of family companionship) on elderly suicide. We find that elderly suicide rate decreases by 8.7% during the Chinese Lunar New Year. In addition, the protective effects are stronger in counties where the typical level of daily family companionship for the elderly is lower. By contrast, we do not find similar protective effects for young and middle-age cohorts. We consider a variety of alternative mechanisms, and conclude that family companionship is an important channel for the protective effects of the Chinese Lunar New Year. Our study calls for greater attention to the mental health status and suicide problem of the elderly, especially with the rapid population aging and increasing prevalence of the “empty-nest” elderly in developing countries.<br><br>Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at <a href=\"http://www.nber.org/papers/w28566\" TARGET=\"_blank\">www.nber.org</a>.<br>","PeriodicalId":19091,"journal":{"name":"NBER Working Paper Series","volume":"31 11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86232798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the absence of first-best climate policy, energy efficiency has figured prominently among strategies to reduce carbon emissions. One of the most sought-after green certification in the building sector is the internationally recognized Leadership in Energy & Environmental Design (LEED). This paper examines the effects of LEED certification on energy efficiency in federally owned buildings. Using propensity score matching and difference in differences models, we find no effect of LEED certification on average energy consumption. This reflects the fact that energy use is one of a number of attributes that receives scores under the LEED program. Buildings with above average energy scores have greater energy efficiency post-certification. Some other attributes, notably higher water scores, decrease energy efficiency post-certification. Trade-offs across LEED attributes account for the absence of energy savings on average. If energy efficiency is the primary policy goal, LEED certification may not be the most effective means to reach that goal.
Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.
{"title":"Does Leed Certification Save Energy? Evidence from Federal Buildings","authors":"Karen Clay, Edson Severnini, Xiaochen Sun","doi":"10.3386/W28612","DOIUrl":"https://doi.org/10.3386/W28612","url":null,"abstract":"In the absence of first-best climate policy, energy efficiency has figured prominently among strategies to reduce carbon emissions. One of the most sought-after green certification in the building sector is the internationally recognized Leadership in Energy & Environmental Design (LEED). This paper examines the effects of LEED certification on energy efficiency in federally owned buildings. Using propensity score matching and difference in differences models, we find no effect of LEED certification on average energy consumption. This reflects the fact that energy use is one of a number of attributes that receives scores under the LEED program. Buildings with above average energy scores have greater energy efficiency post-certification. Some other attributes, notably higher water scores, decrease energy efficiency post-certification. Trade-offs across LEED attributes account for the absence of energy savings on average. If energy efficiency is the primary policy goal, LEED certification may not be the most effective means to reach that goal.<br><br>Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at <a href=\"http://www.nber.org/papers/w28612\" TARGET=\"_blank\">www.nber.org</a>.<br>","PeriodicalId":19091,"journal":{"name":"NBER Working Paper Series","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84403740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In many developing countries today, the structural transformation is a shift of employment out of agriculture into the service sector. By contrast, industrial employment is mostly stagnant. Is the service sector an engine of growth and hence growth service led? Or is its expansion a mere corollary of growth, where rising incomes stemming from productivity growth in goods-producing industries increases the demand for services? To determine whether growth is service led or service biased, we estimate a spatial equilibrium model with nonhomothetic preferences. Our methodology is in the spirit of development accounting and lends itself to a quantitative assessment of both the aggregate and the heterogenous welfare effects of sectoral productivity growth. In an application to India, we find that productivity growth in consumer services such as retail and hospitality was an important driver of rising living standards between 1987 and 2011. However, such benefits were highly skewed and accrued mostly to high-income households living in urbanized locations. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.
{"title":"Service-Led or Service-Biased Growth? Equilibrium Development Accounting Across Indian Districts","authors":"Tianyu Fan, M. Peters, Fabrizio Zilibotti","doi":"10.3386/W28551","DOIUrl":"https://doi.org/10.3386/W28551","url":null,"abstract":"In many developing countries today, the structural transformation is a shift of employment out of agriculture into the service sector. By contrast, industrial employment is mostly stagnant. Is the service sector an engine of growth and hence growth service led? Or is its expansion a mere corollary of growth, where rising incomes stemming from productivity growth in goods-producing industries increases the demand for services? To determine whether growth is service led or service biased, we estimate a spatial equilibrium model with nonhomothetic preferences. Our methodology is in the spirit of development accounting and lends itself to a quantitative assessment of both the aggregate and the heterogenous welfare effects of sectoral productivity growth. In an application to India, we find that productivity growth in consumer services such as retail and hospitality was an important driver of rising living standards between 1987 and 2011. However, such benefits were highly skewed and accrued mostly to high-income households living in urbanized locations. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.","PeriodicalId":19091,"journal":{"name":"NBER Working Paper Series","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84382818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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