In this paper we develop a balanced growth model with labor supply and search and matching frictions in the labor market, to study the impact of economic policy variables on the two margins which constitute the (total) labor input: the extensive margin (the rate of employment) and the intensive margin (the hours worked per worker). We show that the dynamics of taxes primarily have an impact on hours worked, while labor market institutions have a significant influence on the rate of employment. However, our findings emphasize that there is an interaction between the two margins. The model is tested on four countries (US, France, Germany and the UK), which have experienced different tax and labor market dynamics since the sixties. Using this structural approach, we can then perform counterfactual experiments about the evolution of the policy variables, and compare the implications of policy changes in terms of production as well as average welfare.
{"title":"Accounting for Labor Gaps","authors":"F. Langot, Alessandra Pizzo","doi":"10.2139/ssrn.2740960","DOIUrl":"https://doi.org/10.2139/ssrn.2740960","url":null,"abstract":"In this paper we develop a balanced growth model with labor supply and search and matching frictions in the labor market, to study the impact of economic policy variables on the two margins which constitute the (total) labor input: the extensive margin (the rate of employment) and the intensive margin (the hours worked per worker). We show that the dynamics of taxes primarily have an impact on hours worked, while labor market institutions have a significant influence on the rate of employment. However, our findings emphasize that there is an interaction between the two margins. The model is tested on four countries (US, France, Germany and the UK), which have experienced different tax and labor market dynamics since the sixties. Using this structural approach, we can then perform counterfactual experiments about the evolution of the policy variables, and compare the implications of policy changes in terms of production as well as average welfare.","PeriodicalId":101534,"journal":{"name":"Banque de France Research Paper Series","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115293210","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}
Christophe Jadeau, É. Jousselin, S. Roux, G. Verdugo
In coordination with the ECB and 24 other national central banks of the European Union, the Banque de France interrogated 1150 French firms to understand how the crisis affected their economic environment and their human resources practices during the 2010-2013 period. A majority of workers were employed by firms which indicate that their activity was mostly affected by a decrease in demand considered as long-lasting by more than 40% of them, especially in the construction sector and among small firms. In contrast, less than 20% of firms (weighted by their employment) report that the unavailability of credit had an effect on their activity. Over the period, despite the economic downturn, the amount of total costs increased for 70% of firms (weighted by their employment) mainly through an increase in labour costs and secondly in the cost of supplies. In particular, base wages continued to increase for a large share of firms, suggesting strong downward wage rigidities. Many firms indicate substantial difficulties in adjusting the labour force: throughout the crisis it became more difficult to hire qualified employees, to adjust working hours or to move workers to different job positions. The joint presence of difficulties in finding employees and unemployment growth suggest that structural unemployment increased in France in recent years. Other factors considered as significantly constraining for employment growth by a large majority of firms are uncertainty about economic conditions, risks that labour laws are changed, high payroll taxes and firing costs.
{"title":"The Behaviour of French Firms During the Crisis: Evidence from the Wage Dynamics Network Survey","authors":"Christophe Jadeau, É. Jousselin, S. Roux, G. Verdugo","doi":"10.2139/ssrn.2677646","DOIUrl":"https://doi.org/10.2139/ssrn.2677646","url":null,"abstract":"In coordination with the ECB and 24 other national central banks of the European Union, the Banque de France interrogated 1150 French firms to understand how the crisis affected their economic environment and their human resources practices during the 2010-2013 period. A majority of workers were employed by firms which indicate that their activity was mostly affected by a decrease in demand considered as long-lasting by more than 40% of them, especially in the construction sector and among small firms. In contrast, less than 20% of firms (weighted by their employment) report that the unavailability of credit had an effect on their activity. Over the period, despite the economic downturn, the amount of total costs increased for 70% of firms (weighted by their employment) mainly through an increase in labour costs and secondly in the cost of supplies. In particular, base wages continued to increase for a large share of firms, suggesting strong downward wage rigidities. Many firms indicate substantial difficulties in adjusting the labour force: throughout the crisis it became more difficult to hire qualified employees, to adjust working hours or to move workers to different job positions. The joint presence of difficulties in finding employees and unemployment growth suggest that structural unemployment increased in France in recent years. Other factors considered as significantly constraining for employment growth by a large majority of firms are uncertainty about economic conditions, risks that labour laws are changed, high payroll taxes and firing costs.","PeriodicalId":101534,"journal":{"name":"Banque de France Research Paper Series","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123422292","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 this study, we tried to see the impact of military expenditure and foreign aid on foreign direct investment in Sub-Saharan Africa using a panel data analysis. Based on the results obtained from the fixed effect estimation model, Net Official Development Assistance (ODA) can increase the inflow of foreign direct investment in Sub-Saharan African countries. Military expenditure can also increase the inflow of FDI. The result from the estimation is aligned with the argument of some researchers (like Anyanwu (2012) and Jakobsen (2010)) that foreign aid and military expenditure can increase the inflow of foreign direct investment to developing countries, including Sub-Saharan African countries.
{"title":"Foreign Direct Investment, Military Expenditure and Foreign Aid in Sub-Saharan Africa (Panel Data Analysis)","authors":"M. A. Workneh","doi":"10.2139/ssrn.3689786","DOIUrl":"https://doi.org/10.2139/ssrn.3689786","url":null,"abstract":"In this study, we tried to see the impact of military expenditure and foreign aid on foreign direct investment in Sub-Saharan Africa using a panel data analysis. Based on the results obtained from the fixed effect estimation model, Net Official Development Assistance (ODA) can increase the inflow of foreign direct investment in Sub-Saharan African countries. Military expenditure can also increase the inflow of FDI. The result from the estimation is aligned with the argument of some researchers (like Anyanwu (2012) and Jakobsen (2010)) that foreign aid and military expenditure can increase the inflow of foreign direct investment to developing countries, including Sub-Saharan African countries.","PeriodicalId":101534,"journal":{"name":"Banque de France Research Paper Series","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125230556","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}
This paper proposes a classification of the old member countries of the euro area in a structural data rich environment and run a convergence analysis using the same framework. First, we use a clustering approach and identify two structurally distinct groups of countries that are not modified between 1995 and 2007: the South Countries Group (SCG) – composed of Greece, Italy, Portugal and Spain – and the Other Countries Group (OCG). Second, we propose a convergence metrics and reach three key findings: (i) increase over time of the between-group dispersion; (ii) diverging demographics and innovation performance into the OCG, and (iii) an unfortunate convergence towards high labour market duality in the SCG.
{"title":"Euro Area Structural Convergence? A Multi-Criterion Cluster Analysis","authors":"Delphine M. Irac, Jimmy Lopez","doi":"10.2139/ssrn.2374369","DOIUrl":"https://doi.org/10.2139/ssrn.2374369","url":null,"abstract":"This paper proposes a classification of the old member countries of the euro area in a structural data rich environment and run a convergence analysis using the same framework. First, we use a clustering approach and identify two structurally distinct groups of countries that are not modified between 1995 and 2007: the South Countries Group (SCG) – composed of Greece, Italy, Portugal and Spain – and the Other Countries Group (OCG). Second, we propose a convergence metrics and reach three key findings: (i) increase over time of the between-group dispersion; (ii) diverging demographics and innovation performance into the OCG, and (iii) an unfortunate convergence towards high labour market duality in the SCG.","PeriodicalId":101534,"journal":{"name":"Banque de France Research Paper Series","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133936112","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}
This paper analyzes a two-country model of currency, banks and endogenous default to study whether impediments to credit market integration across jurisdictions impact the desirability of a currency union. We show that when those impediments induce a higher cost for banks to manage cross-border credit compared to domestic credit, welfare may not be maximal under a regime of currency union. But a banking union that would suppress hurdles to banking integration restores the optimality of that currency arrangement. The empirical and policy implications in terms of banking union are discussed.
{"title":"Currency Union with and Without Banking Union","authors":"V. Bignon, Régis Breton, Mariana Rojas Breu","doi":"10.2139/ssrn.2335960","DOIUrl":"https://doi.org/10.2139/ssrn.2335960","url":null,"abstract":"This paper analyzes a two-country model of currency, banks and endogenous default to study whether impediments to credit market integration across jurisdictions impact the desirability of a currency union. We show that when those impediments induce a higher cost for banks to manage cross-border credit compared to domestic credit, welfare may not be maximal under a regime of currency union. But a banking union that would suppress hurdles to banking integration restores the optimality of that currency arrangement. The empirical and policy implications in terms of banking union are discussed.","PeriodicalId":101534,"journal":{"name":"Banque de France Research Paper Series","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124900037","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}
The recent boom and bust in commodity prices has renewed the policymakers' interest in three complementary issues: i) characteristics and determinants of commodity price instability, ii) its macroeconomic effects and, iii) the optimal policy responses to this instability. This work falls within the scope of studies dedicated to the macroeconomic effects of commodity price instability, but focuses on the impact on public finance, while existing works were concentrated on growth. This paper also differs from the few previous studies on two aspects. First, we test the impact of commodity price volatility rather than focusing only on price levels. Second, we use disaggregated data on tax revenues (income tax, consumption tax and international trade tax) and on commodity prices (agricultural products, minerals and energy) in order to identify transmission channels between world prices and public finance variables. Our empirical analysis is carried out on 90 developing countries over 1980-2008. We compute an index which measures the volatility of the international price of 41 commodities in the sectors of agriculture, minerals and energy. We find robust evidence that tax revenues in developing countries increase with the rise of commodity prices but that they are hurt by the volatility of these prices. More specifically, price short-run volatility of imported commodities hurts tax revenues through trade and consumption taxes, while price medium-run volatility of export hurts tax revenues through both indirect and direct taxes. These findings point at the detrimental effect of commodity price volatility on developing countries public finances and highlight further the importance of finding ways to limit this price volatility and to implement policy measures to mitigate its adverse effects.
{"title":"Commodity Price Volatility and Tax Revenue: Evidence from Developing Countries","authors":"H. Ehrhart, S. Guérineau","doi":"10.2139/ssrn.2225300","DOIUrl":"https://doi.org/10.2139/ssrn.2225300","url":null,"abstract":"The recent boom and bust in commodity prices has renewed the policymakers' interest in three complementary issues: i) characteristics and determinants of commodity price instability, ii) its macroeconomic effects and, iii) the optimal policy responses to this instability. This work falls within the scope of studies dedicated to the macroeconomic effects of commodity price instability, but focuses on the impact on public finance, while existing works were concentrated on growth. This paper also differs from the few previous studies on two aspects. First, we test the impact of commodity price volatility rather than focusing only on price levels. Second, we use disaggregated data on tax revenues (income tax, consumption tax and international trade tax) and on commodity prices (agricultural products, minerals and energy) in order to identify transmission channels between world prices and public finance variables. Our empirical analysis is carried out on 90 developing countries over 1980-2008. We compute an index which measures the volatility of the international price of 41 commodities in the sectors of agriculture, minerals and energy. We find robust evidence that tax revenues in developing countries increase with the rise of commodity prices but that they are hurt by the volatility of these prices. More specifically, price short-run volatility of imported commodities hurts tax revenues through trade and consumption taxes, while price medium-run volatility of export hurts tax revenues through both indirect and direct taxes. These findings point at the detrimental effect of commodity price volatility on developing countries public finances and highlight further the importance of finding ways to limit this price volatility and to implement policy measures to mitigate its adverse effects.","PeriodicalId":101534,"journal":{"name":"Banque de France Research Paper Series","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124892731","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}
F. Collard, Harris Dellas, B. Diba, Olivier Loisel
The recent financial crisis has highlighted the interconnectedness between macroeconomic and financial stability and has raised the question of whether and how to combine the corresponding main policy instruments (interest rate and bank-capital requirements). This paper offers a characterization of the jointly optimal setting of monetary and prudential policies and discusses its implications for the business cycle. The source of financial fragility is the socially excessive risk-taking by banks due to limited liability and deposit insurance. We characterize the conditions under which locally optimal (Ramsey) policy dedicates the prudential instrument to preventing inefficient risk-taking by banks; and the monetary instrument to dealing with the business cycle, with the two instruments co-varying negatively. Our analysis thus identifies circumstances that can validate the prevailing view among central bankers that standard interest-rate policy cannot serve as the first line of defense against financial instability. In addition, we also provide conditions under which the two instruments might optimally co-move positively and countercyclically.
{"title":"Optimal Monetary and Prudential Policies","authors":"F. Collard, Harris Dellas, B. Diba, Olivier Loisel","doi":"10.2139/ssrn.2192467","DOIUrl":"https://doi.org/10.2139/ssrn.2192467","url":null,"abstract":"The recent financial crisis has highlighted the interconnectedness between macroeconomic and financial stability and has raised the question of whether and how to combine the corresponding main policy instruments (interest rate and bank-capital requirements). This paper offers a characterization of the jointly optimal setting of monetary and prudential policies and discusses its implications for the business cycle. The source of financial fragility is the socially excessive risk-taking by banks due to limited liability and deposit insurance. We characterize the conditions under which locally optimal (Ramsey) policy dedicates the prudential instrument to preventing inefficient risk-taking by banks; and the monetary instrument to dealing with the business cycle, with the two instruments co-varying negatively. Our analysis thus identifies circumstances that can validate the prevailing view among central bankers that standard interest-rate policy cannot serve as the first line of defense against financial instability. In addition, we also provide conditions under which the two instruments might optimally co-move positively and countercyclically.","PeriodicalId":101534,"journal":{"name":"Banque de France Research Paper Series","volume":"22 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133141823","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}
This paper explores the existence of a bounce-back effect in inventory investment using the European Commission opinion survey on stocks of finished products in manufacturing and retail trade sectors. The data are quarterly balance for France, Germany and a European aggregate, from 1985q1 to 2011q4. Our empirical findings support the existence of a high recovery episode for inventory investment, during the quarters immediately following the recessions. This could in turn explain the real GDP growth rate bounce-back pointed out in previous empirical studies. Moreover, according to our estimates, the inventory investment bounce-back occurs later and lasts longer in manufacturing than in retail trade sector.
{"title":"Inventory Investment Dynamics and Recoveries: A Comparison of Manufacturing and Retail Trade Sectors","authors":"F. Bec, Marie Bessec","doi":"10.2139/ssrn.2161796","DOIUrl":"https://doi.org/10.2139/ssrn.2161796","url":null,"abstract":"This paper explores the existence of a bounce-back effect in inventory investment using the European Commission opinion survey on stocks of finished products in manufacturing and retail trade sectors. The data are quarterly balance for France, Germany and a European aggregate, from 1985q1 to 2011q4. Our empirical findings support the existence of a high recovery episode for inventory investment, during the quarters immediately following the recessions. This could in turn explain the real GDP growth rate bounce-back pointed out in previous empirical studies. Moreover, according to our estimates, the inventory investment bounce-back occurs later and lasts longer in manufacturing than in retail trade sector.","PeriodicalId":101534,"journal":{"name":"Banque de France Research Paper Series","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134336349","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}
The study presents review of the Magharib countries economic bloc which consists of Algeria, Libya, Morocco, Tunisia and Mauritania. The feasibility of that economic bloc concludes its potentials. There comparative advantages for each county to integrate with the others in production factors and products, surplus labor in Mauritania and shortages in Libya, surplus agricultural production in Morocco and Tunisia, Morocco and shortages in Mauritania and Libya, energy surplus in Libya and shortages in Mauritania, Tunisia and surplus in Libya. However, the review of the institutional structure of its dynamics reveals that it is politically controlled and it is more or less motivated by individual country impulses. De facto application of trade enhancements and motivation do not exist. Economic boundaries, e.g., trade taxation and tariffs reduce possible exchange without economic sense. I hereby conclude that the main hindrance of potentiating trade and transference, e.g., cross border, tariffs and production factors. Different political regimes seem to be the primary hindrance which reduces chances of economic development. I propose here that such condition cannot support the modus operandi of that economic bloc and that joining the French African Economic Bloc will do better in integrating economies of those West African countries.
{"title":"Review of the Arabic Magharib Economic Bloc","authors":"Issam A.W. Mohamed","doi":"10.2139/ssrn.2043095","DOIUrl":"https://doi.org/10.2139/ssrn.2043095","url":null,"abstract":"The study presents review of the Magharib countries economic bloc which consists of Algeria, Libya, Morocco, Tunisia and Mauritania. The feasibility of that economic bloc concludes its potentials. There comparative advantages for each county to integrate with the others in production factors and products, surplus labor in Mauritania and shortages in Libya, surplus agricultural production in Morocco and Tunisia, Morocco and shortages in Mauritania and Libya, energy surplus in Libya and shortages in Mauritania, Tunisia and surplus in Libya. However, the review of the institutional structure of its dynamics reveals that it is politically controlled and it is more or less motivated by individual country impulses. De facto application of trade enhancements and motivation do not exist. Economic boundaries, e.g., trade taxation and tariffs reduce possible exchange without economic sense. I hereby conclude that the main hindrance of potentiating trade and transference, e.g., cross border, tariffs and production factors. Different political regimes seem to be the primary hindrance which reduces chances of economic development. I propose here that such condition cannot support the modus operandi of that economic bloc and that joining the French African Economic Bloc will do better in integrating economies of those West African countries.","PeriodicalId":101534,"journal":{"name":"Banque de France Research Paper Series","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116198654","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}
It is well known that weighted averages of two competing forecasts may reduce Mean Squared Prediction Errors (MSPE) and may also introduce certain inefficiencies. In this paper we take an in-depth view of one particular type of inefficiency stemming from simple combination schemes. We identify testable conditions under which every linear convex combination of two forecasts displays this type of inefficiency. In particular, we show that the process of taking averages of forecasts may induce inefficiencies in the combination, even when the individual forecasts are efficient. Furthermore, we show that the so-called "optimal weighted average" traditionally presented in the literature may indeed be suboptimal. We propose a simple testable condition to detect if this traditional weighted factor is optimal in a broader sense. An optimal "recombination weight" is introduced. Finally, we illustrate our findings with simulations and an empirical application in the context of the combination of inflation forecasts.
{"title":"Are Forecast Combinations Efficient?","authors":"Pablo M. Pincheira","doi":"10.2139/ssrn.2039670","DOIUrl":"https://doi.org/10.2139/ssrn.2039670","url":null,"abstract":"It is well known that weighted averages of two competing forecasts may reduce Mean Squared Prediction Errors (MSPE) and may also introduce certain inefficiencies. In this paper we take an in-depth view of one particular type of inefficiency stemming from simple combination schemes. We identify testable conditions under which every linear convex combination of two forecasts displays this type of inefficiency. In particular, we show that the process of taking averages of forecasts may induce inefficiencies in the combination, even when the individual forecasts are efficient. Furthermore, we show that the so-called \"optimal weighted average\" traditionally presented in the literature may indeed be suboptimal. We propose a simple testable condition to detect if this traditional weighted factor is optimal in a broader sense. An optimal \"recombination weight\" is introduced. Finally, we illustrate our findings with simulations and an empirical application in the context of the combination of inflation forecasts.","PeriodicalId":101534,"journal":{"name":"Banque de France Research Paper Series","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131002946","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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