Abstract Using Danish matched employer-employee data, I compare the relative pay of men and women to their relative productivity as measured by production function estimation. I find that the gender “productivity gap” is 8%, implying that almost two thirds of the residual gender wage gap is due to productivity differences between men and women. Motherhood plays an important role, yet it also reveals a puzzle: the pay gap for mothers is entirely explained by productivity, whereas the gap for non-mothers is not. In addition, the decoupling of pay and productivity for women without children happens during their prime-child bearing years. These estimates are robust to a variety of specifications for the impact of observables on productivity, and robust to accounting for endogenous sorting of women into less productive firms using a control-function approach. This paper also provides estimates of the productivity gap across industries and occupations, finding the same general patterns for mothers compared to women without children within these subgroups.
{"title":"Motherhood and the Gender Productivity Gap","authors":"Yana Gallen","doi":"10.1093/jeea/jvad064","DOIUrl":"https://doi.org/10.1093/jeea/jvad064","url":null,"abstract":"Abstract Using Danish matched employer-employee data, I compare the relative pay of men and women to their relative productivity as measured by production function estimation. I find that the gender “productivity gap” is 8%, implying that almost two thirds of the residual gender wage gap is due to productivity differences between men and women. Motherhood plays an important role, yet it also reveals a puzzle: the pay gap for mothers is entirely explained by productivity, whereas the gap for non-mothers is not. In addition, the decoupling of pay and productivity for women without children happens during their prime-child bearing years. These estimates are robust to a variety of specifications for the impact of observables on productivity, and robust to accounting for endogenous sorting of women into less productive firms using a control-function approach. This paper also provides estimates of the productivity gap across industries and occupations, finding the same general patterns for mothers compared to women without children within these subgroups.","PeriodicalId":48297,"journal":{"name":"Journal of the European Economic Association","volume":"2011 15","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Decisions under uncertainty are often made with information whose interpretation is uncertain because multiple interpretations are possible. Individuals may perceive and handle uncertainty about interpretation differently and in ways that are not directly observable to a modeler. This paper identifies and experimentally examines behavior that can be interpreted as reflecting an individual’s attitude towards such uncertainty.
{"title":"Hard-to-Interpret Signals","authors":"Larry G Epstein, Yoram Halevy","doi":"10.1093/jeea/jvad062","DOIUrl":"https://doi.org/10.1093/jeea/jvad062","url":null,"abstract":"Abstract Decisions under uncertainty are often made with information whose interpretation is uncertain because multiple interpretations are possible. Individuals may perceive and handle uncertainty about interpretation differently and in ways that are not directly observable to a modeler. This paper identifies and experimentally examines behavior that can be interpreted as reflecting an individual’s attitude towards such uncertainty.","PeriodicalId":48297,"journal":{"name":"Journal of the European Economic Association","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135567601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maristella Botticini, Pietro Buri, Massimo Marinacci
Abstract Maritime insurance developed in medieval Europe is the ancestor of all forms of insurance that appeared subsequently. We address the question of why modern insurance was first invented in medieval Europe, and neither earlier nor elsewhere. Drawing from insights from the literature on uncertainty aversion, we show that medieval merchants had to bear more frequently natural risks (they traveled longer distances) and new human risks with unknown probabilities (they faced unpredictable attacks by corsairs due to increased political fragmentation and commercial competition in Europe). The increased demand for protection in medieval seaborne trade met the supply of protection by a small group of wealthy merchants with a broad information network who could pool risks and profit from selling protection through a novel business device: the insurance contract. A new market—the market for insurance—was then born. Next, analyzing more than seven thousand insurance contracts redacted by notaries and about one hundred court proceedings housed in the archives of Barcelona, Florence, Genoa, Palermo, Prato, and Venice, we study the main features of medieval trade, the type of risks faced by merchants, and the characteristics of insurance contracts and markets from 1340 to 1500. The empirical analysis delivers two main findings. First, risks related to human activities (e.g., attacks by corsairs) seem to have had a relatively greater impact on insurance premia compared to natural risks (proxied by seasonal risks). Second, distance mattered but the route seems to have had a greater impact on insurance premia. Specific routes (e.g., in the Tyrrenian and the western Mediterranean) were more plagued by human risks, which were harder to avoid for the majority of merchants who did not have a broad information network compared to the few wealthy merchants, who became the key players in selling insurance in the early stages of the development of insurance markets.
{"title":"The Beauty of Uncertainty: The Rise of Insurance Contracts and Markets in Medieval Europe","authors":"Maristella Botticini, Pietro Buri, Massimo Marinacci","doi":"10.1093/jeea/jvad059","DOIUrl":"https://doi.org/10.1093/jeea/jvad059","url":null,"abstract":"Abstract Maritime insurance developed in medieval Europe is the ancestor of all forms of insurance that appeared subsequently. We address the question of why modern insurance was first invented in medieval Europe, and neither earlier nor elsewhere. Drawing from insights from the literature on uncertainty aversion, we show that medieval merchants had to bear more frequently natural risks (they traveled longer distances) and new human risks with unknown probabilities (they faced unpredictable attacks by corsairs due to increased political fragmentation and commercial competition in Europe). The increased demand for protection in medieval seaborne trade met the supply of protection by a small group of wealthy merchants with a broad information network who could pool risks and profit from selling protection through a novel business device: the insurance contract. A new market—the market for insurance—was then born. Next, analyzing more than seven thousand insurance contracts redacted by notaries and about one hundred court proceedings housed in the archives of Barcelona, Florence, Genoa, Palermo, Prato, and Venice, we study the main features of medieval trade, the type of risks faced by merchants, and the characteristics of insurance contracts and markets from 1340 to 1500. The empirical analysis delivers two main findings. First, risks related to human activities (e.g., attacks by corsairs) seem to have had a relatively greater impact on insurance premia compared to natural risks (proxied by seasonal risks). Second, distance mattered but the route seems to have had a greater impact on insurance premia. Specific routes (e.g., in the Tyrrenian and the western Mediterranean) were more plagued by human risks, which were harder to avoid for the majority of merchants who did not have a broad information network compared to the few wealthy merchants, who became the key players in selling insurance in the early stages of the development of insurance markets.","PeriodicalId":48297,"journal":{"name":"Journal of the European Economic Association","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136178133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This paper proposes a tractable way to model boundedly rational dynamic programming. The agent uses an endogenously simplified, or “sparse,” model of the world and the consequences of his actions and acts according to a behavioral Bellman equation. The framework yields a behavioral version of some of the canonical models in macroeconomics and finance. In the life-cycle model, the agent initially does not pay much attention to retirement and undersaves; late in life, he progressively saves more, generating realistic dynamics. In the consumption-savings model, the consumer decides to pay little or no attention to the interest rate and more attention to his income. Ricardian equivalence and the Lucas critique partially fail because the consumer may not pay full attention to taxes and policy changes. In a Merton-style dynamic portfolio choice problem, the agent endogenously pays limited or no attention to the varying equity premium and hedging demand terms. Finally, in the neoclassical growth model, agents act on a simplified model of the macroeconomy; in equilibrium, fluctuations are larger and more persistent.
{"title":"Behavioral Macroeconomics VIA Sparse Dynamic Programming","authors":"Xavier Gabaix","doi":"10.1093/jeea/jvad057","DOIUrl":"https://doi.org/10.1093/jeea/jvad057","url":null,"abstract":"Abstract This paper proposes a tractable way to model boundedly rational dynamic programming. The agent uses an endogenously simplified, or “sparse,” model of the world and the consequences of his actions and acts according to a behavioral Bellman equation. The framework yields a behavioral version of some of the canonical models in macroeconomics and finance. In the life-cycle model, the agent initially does not pay much attention to retirement and undersaves; late in life, he progressively saves more, generating realistic dynamics. In the consumption-savings model, the consumer decides to pay little or no attention to the interest rate and more attention to his income. Ricardian equivalence and the Lucas critique partially fail because the consumer may not pay full attention to taxes and policy changes. In a Merton-style dynamic portfolio choice problem, the agent endogenously pays limited or no attention to the varying equity premium and hedging demand terms. Finally, in the neoclassical growth model, agents act on a simplified model of the macroeconomy; in equilibrium, fluctuations are larger and more persistent.","PeriodicalId":48297,"journal":{"name":"Journal of the European Economic Association","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136058225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract We study how social media affects election outcomes in the United States. We use variation in the number of Twitter users across counties induced by early adopters at the 2007 South by Southwest (SXSW) festival, a key event in Twitter’s rise to popularity. We show that this variation is unrelated to observable county characteristics and electoral outcomes before the launch of Twitter. Our results indicate that Twitter lowered the Republican vote share in the 2016 and 2020 presidential elections, but had limited effects on Congressional elections and previous presidential elections. Evidence from survey data, primary elections, and text analysis of millions of tweets suggests that Twitter’s relatively liberal content may have persuaded voters with moderate views to vote against Donald Trump.
{"title":"The Effect of Social Media on Elections: Evidence from the United States","authors":"Thomas Fujiwara, Karsten Müller, Carlo Schwarz","doi":"10.1093/jeea/jvad058","DOIUrl":"https://doi.org/10.1093/jeea/jvad058","url":null,"abstract":"Abstract We study how social media affects election outcomes in the United States. We use variation in the number of Twitter users across counties induced by early adopters at the 2007 South by Southwest (SXSW) festival, a key event in Twitter’s rise to popularity. We show that this variation is unrelated to observable county characteristics and electoral outcomes before the launch of Twitter. Our results indicate that Twitter lowered the Republican vote share in the 2016 and 2020 presidential elections, but had limited effects on Congressional elections and previous presidential elections. Evidence from survey data, primary elections, and text analysis of millions of tweets suggests that Twitter’s relatively liberal content may have persuaded voters with moderate views to vote against Donald Trump.","PeriodicalId":48297,"journal":{"name":"Journal of the European Economic Association","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136212814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This paper shows that inattention to taxes generates a time-inconsistency problem in the choice of tax policy, leading to higher taxes in equilibrium. These discretionary tax increases are inefficient as they are deviations from the socially optimal commitment policy. We call these deviations a taxation bias. Combining sufficient statistics and structural approaches, we quantify the magnitude of this policy distortion for the U.S. redistributive tax-transfer system. We find that the taxation bias ranges between 3 and 8 percentage points, alters tax-transfer progressivity, and has significant welfare effects. Overall, our findings shed new light on the implications of inattention and misperceptions.
{"title":"Inattention and the Taxation Bias","authors":"Jérémy Boccanfuso, Antoine Ferey","doi":"10.1093/jeea/jvad056","DOIUrl":"https://doi.org/10.1093/jeea/jvad056","url":null,"abstract":"Abstract This paper shows that inattention to taxes generates a time-inconsistency problem in the choice of tax policy, leading to higher taxes in equilibrium. These discretionary tax increases are inefficient as they are deviations from the socially optimal commitment policy. We call these deviations a taxation bias. Combining sufficient statistics and structural approaches, we quantify the magnitude of this policy distortion for the U.S. redistributive tax-transfer system. We find that the taxation bias ranges between 3 and 8 percentage points, alters tax-transfer progressivity, and has significant welfare effects. Overall, our findings shed new light on the implications of inattention and misperceptions.","PeriodicalId":48297,"journal":{"name":"Journal of the European Economic Association","volume":"168 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135302167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The pessimistic bias and the cross-sectional dispersion of households’ subjective beliefs heighten during recessions. We provide empirical evidence for a dominant non-inflationary aggregate demand shock that accounts for the bulk of business-cycle fluctuations not only in real quantities but also in (1) pessimism—to what degree households are more pessimistic than the rational expectation benchmark and (2) disagreement—the cross-sectional dispersion of households’ beliefs. To rationalize the empirical findings, this paper develops a theory of ambiguity-driven business cycles, where the Bayesian formulation of the ambiguity shock can generate positive co-movements across real quantities together with counter-cyclical pessimism and disagreement within the real business-cycle framework. Our theory reproduces the salient features of the business cycles extended with survey data on households’ expectations. Quantitatively, the ambiguity shock alone accounts for a significant fraction of the business-cycle fluctuations in pessimism, disagreement, and real quantities.
{"title":"Pessimism, Disagreement, and Economic Fluctuations","authors":"Guangyu Pei","doi":"10.1093/jeea/jvad055","DOIUrl":"https://doi.org/10.1093/jeea/jvad055","url":null,"abstract":"Abstract The pessimistic bias and the cross-sectional dispersion of households’ subjective beliefs heighten during recessions. We provide empirical evidence for a dominant non-inflationary aggregate demand shock that accounts for the bulk of business-cycle fluctuations not only in real quantities but also in (1) pessimism—to what degree households are more pessimistic than the rational expectation benchmark and (2) disagreement—the cross-sectional dispersion of households’ beliefs. To rationalize the empirical findings, this paper develops a theory of ambiguity-driven business cycles, where the Bayesian formulation of the ambiguity shock can generate positive co-movements across real quantities together with counter-cyclical pessimism and disagreement within the real business-cycle framework. Our theory reproduces the salient features of the business cycles extended with survey data on households’ expectations. Quantitatively, the ambiguity shock alone accounts for a significant fraction of the business-cycle fluctuations in pessimism, disagreement, and real quantities.","PeriodicalId":48297,"journal":{"name":"Journal of the European Economic Association","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135458560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Colonial trade prompted the colonies to specialise in primary products. Did this eliminate industrialisation opportunities in the colonies, and did it make them more politically dependent on the coloniser? To answer these questions, we examine the impact of the World War I trade shock on industrial growth and support for the anti-colonial movement in India. We find that districts more exposed to a drop in imports experienced faster industrial growth in 1911–1921, thereafter remaining on a higher level of industrial employment. All evidence points to an increase in Indian productivities as the reason for this, suggesting that liberal trade policies may not have been optimal for colonial India. We also find that districts, which industrialised faster thanks to WWI were more likely to support the Indian National Congress. This is consistent with the view that specialisation in primary products made the colonies more politically dependent on the coloniser.
{"title":"Trade Disruption, Industrialisation, and the Setting Sun of British Colonial Rule in India","authors":"Roberto Bonfatti, Björn Brey","doi":"10.1093/jeea/jvad054","DOIUrl":"https://doi.org/10.1093/jeea/jvad054","url":null,"abstract":"Abstract Colonial trade prompted the colonies to specialise in primary products. Did this eliminate industrialisation opportunities in the colonies, and did it make them more politically dependent on the coloniser? To answer these questions, we examine the impact of the World War I trade shock on industrial growth and support for the anti-colonial movement in India. We find that districts more exposed to a drop in imports experienced faster industrial growth in 1911–1921, thereafter remaining on a higher level of industrial employment. All evidence points to an increase in Indian productivities as the reason for this, suggesting that liberal trade policies may not have been optimal for colonial India. We also find that districts, which industrialised faster thanks to WWI were more likely to support the Indian National Congress. This is consistent with the view that specialisation in primary products made the colonies more politically dependent on the coloniser.","PeriodicalId":48297,"journal":{"name":"Journal of the European Economic Association","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136119566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Margherita Borella, Mariacristina De Nardi, Michael Pak, Nicolo Russo, Fang Yang
Abstract The structure of taxes and their burden have undergone large and frequent changes over time. We provide a brief history of U.S. federal income tax reform since the 1960s, calculate effective federal income tax rates for each wave of the Panel Study of Income Dynamics, and discuss how effective taxation changed from 1969 to 2016. We show that most tax regimes are short-lived and that the variation in taxes over time and across groups is large. We also use an estimated dynamic model of couples and singles to show that the various tax regimes that we estimate imply very different labor market and saving behavior. These findings stress the importance of studying and modeling tax changes over time and across groups.
{"title":"The Importance of Modeling Income Taxes Over Time: U.S. Reforms and Outcomes","authors":"Margherita Borella, Mariacristina De Nardi, Michael Pak, Nicolo Russo, Fang Yang","doi":"10.1093/jeea/jvad053","DOIUrl":"https://doi.org/10.1093/jeea/jvad053","url":null,"abstract":"Abstract The structure of taxes and their burden have undergone large and frequent changes over time. We provide a brief history of U.S. federal income tax reform since the 1960s, calculate effective federal income tax rates for each wave of the Panel Study of Income Dynamics, and discuss how effective taxation changed from 1969 to 2016. We show that most tax regimes are short-lived and that the variation in taxes over time and across groups is large. We also use an estimated dynamic model of couples and singles to show that the various tax regimes that we estimate imply very different labor market and saving behavior. These findings stress the importance of studying and modeling tax changes over time and across groups.","PeriodicalId":48297,"journal":{"name":"Journal of the European Economic Association","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135438418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vincenzo Atella, Edoardo Di Porto, Joanna Kopinska, Maarten Lindeboom
Abstract This paper examines the causal effect of a traumatic event experienced by pregnant women on the life-long labor market outcomes of their offspring. We exploit a unique natural experiment that involved randomly placed Nazi raids in municipalities in Italy during WWII. We link administrative data on male private sector workers to information about Nazi raids and war casualties. Our results suggest that prenatal exposure to traumatic events affects offspring earnings throughout the working career and in retirement. The lower earnings are due to lower educational attainment, the type of jobs held, and interruptions in working careers due to unemployment. We further find that prenatal exposure exacerbates the adverse effects of later-life job loss on earnings. We use a medical database on health expenditures to interpret the effect estimates. The prenatally exposed have higher medical expenditures on diseases of the nervous system and mental disorders, indicating that stress is likely to be an important factor driving our findings.
{"title":"Traumatic Experiences Adversely Affect Life Cycle Labor Market Outcomes of the Next Generation - Evidence from Wwii Nazi Raids","authors":"Vincenzo Atella, Edoardo Di Porto, Joanna Kopinska, Maarten Lindeboom","doi":"10.1093/jeea/jvad052","DOIUrl":"https://doi.org/10.1093/jeea/jvad052","url":null,"abstract":"Abstract This paper examines the causal effect of a traumatic event experienced by pregnant women on the life-long labor market outcomes of their offspring. We exploit a unique natural experiment that involved randomly placed Nazi raids in municipalities in Italy during WWII. We link administrative data on male private sector workers to information about Nazi raids and war casualties. Our results suggest that prenatal exposure to traumatic events affects offspring earnings throughout the working career and in retirement. The lower earnings are due to lower educational attainment, the type of jobs held, and interruptions in working careers due to unemployment. We further find that prenatal exposure exacerbates the adverse effects of later-life job loss on earnings. We use a medical database on health expenditures to interpret the effect estimates. The prenatally exposed have higher medical expenditures on diseases of the nervous system and mental disorders, indicating that stress is likely to be an important factor driving our findings.","PeriodicalId":48297,"journal":{"name":"Journal of the European Economic Association","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135320060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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