Abstract The demand for two composite goods, food away from home (FAFH) and prepared food (PF), are trending upward in Japan as Japanese society ages. This paper estimates the demand function of FAFH and PF. We adopt the almost ideal demand system and predict the effect on future demand from age and cohort changes. We find that the age effect decreases both while the cohort effect increases the share of FAFH but decreases that of PF. Over time, the demand for FAFH gradually decreases but remains stable. The demand for PF has been decreasing as of 2010 and more quickly than for FAFH. The reason is that both the age effect and the dynamic population trend decrease the demand for both goods, while the cohort effect slows the decrease in demand for FAFH but accelerates that for PF.
{"title":"The Future of Demand for Food Away from Home and Prepared Food: Cohort and Age Effects in Japan","authors":"S. Fujioka, M. Fukushige","doi":"10.1515/jafio-2017-0038","DOIUrl":"https://doi.org/10.1515/jafio-2017-0038","url":null,"abstract":"Abstract The demand for two composite goods, food away from home (FAFH) and prepared food (PF), are trending upward in Japan as Japanese society ages. This paper estimates the demand function of FAFH and PF. We adopt the almost ideal demand system and predict the effect on future demand from age and cohort changes. We find that the age effect decreases both while the cohort effect increases the share of FAFH but decreases that of PF. Over time, the demand for FAFH gradually decreases but remains stable. The demand for PF has been decreasing as of 2010 and more quickly than for FAFH. The reason is that both the age effect and the dynamic population trend decrease the demand for both goods, while the cohort effect slows the decrease in demand for FAFH but accelerates that for PF.","PeriodicalId":52541,"journal":{"name":"Journal of Agricultural and Food Industrial Organization","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/jafio-2017-0038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45283794","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}
Abstract Over the last couple of years, the production amount of feed and the market concentration of the feed industry vastly increased in North-Western Germany. This development might lead to asymmetric price transmission of feed between regions in Germany because feed markets in other regions grow slower and therefore decline in relative volume and importance. To analyze this development, the objective of the study was to quantify price relationships of pig, hens and calves feed prices between Western Lower Saxony, Eastern Lower Saxony and Westphalia. Assuming Western Lower Saxony as the central market and using monthly price observation from 2007 until 2017, the results show that the feed prices were co-integrated across regions and type of feed. The results show a tendency of asymmetric price transmission for pig feed between Western Lower Saxony and Eastern Lower Saxony but this was not statistically significant at the 5 % level. Furthermore, we also tested the influence of the feed scandals dioxin in pig feed and mold in imported maize from Serbia, but we could not estimate a pattern of price adjustments between regions according to the feed scandals. Summarizing the results, we came to the conclusion that feed prices might be perfectly transmitted across regions and independently from feed scandals and type of feed.
{"title":"Market Structure of the Feed Industry in Germany: Causing Asymmetric Spatial Price Transmission?","authors":"H. Schulte, O. Musshoff","doi":"10.1515/jafio-2018-0007","DOIUrl":"https://doi.org/10.1515/jafio-2018-0007","url":null,"abstract":"Abstract Over the last couple of years, the production amount of feed and the market concentration of the feed industry vastly increased in North-Western Germany. This development might lead to asymmetric price transmission of feed between regions in Germany because feed markets in other regions grow slower and therefore decline in relative volume and importance. To analyze this development, the objective of the study was to quantify price relationships of pig, hens and calves feed prices between Western Lower Saxony, Eastern Lower Saxony and Westphalia. Assuming Western Lower Saxony as the central market and using monthly price observation from 2007 until 2017, the results show that the feed prices were co-integrated across regions and type of feed. The results show a tendency of asymmetric price transmission for pig feed between Western Lower Saxony and Eastern Lower Saxony but this was not statistically significant at the 5 % level. Furthermore, we also tested the influence of the feed scandals dioxin in pig feed and mold in imported maize from Serbia, but we could not estimate a pattern of price adjustments between regions according to the feed scandals. Summarizing the results, we came to the conclusion that feed prices might be perfectly transmitted across regions and independently from feed scandals and type of feed.","PeriodicalId":52541,"journal":{"name":"Journal of Agricultural and Food Industrial Organization","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/jafio-2018-0007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45423013","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}
Abstract The 2003 CAP Reform commenced a liberal shift on the policies designed to protect farmers across Europe. The CAP Health Check of 2008 and the 2013 CAP Reform confirmed this change, adopting measures including the further decoupling of production, the abolishment of set-aside and the phasing-out of milk quotas. It is therefore expected that price transmission has been affected radically. This study investigates the price transmission mechanism along the European food supply chain, based on an asymmetric panel vector error correction model (VECM). Panel data on agricultural commodity (farmer), producer (processor) and consumer (retailer) prices from nineteen European countries are considered. The sample is split into two sub-periods, before and after the CAP Health Check, to examine how the price transmission mechanism has been affected. Cointegration is confirmed among the price series through the Pedroni tests and the long-run relationship is obtained with two estimation methods (i. e. fully modified OLS and dynamic OLS). Prior to the CAP Health Check, positive asymmetry is detected from farmer to processor and from processor to retailer. However, after the CAP Health Check price transmission becomes symmetric, thus suggesting that decreased support has resulted in a more efficient price transmission mechanism.
{"title":"Asymmetric Price Transmission along the European Food Supply Chain and the CAP Health Check: a Panel Vector Error Correction Approach","authors":"A. Rezitis, Andreas Rokopanos","doi":"10.1515/jafio-2018-0002","DOIUrl":"https://doi.org/10.1515/jafio-2018-0002","url":null,"abstract":"Abstract The 2003 CAP Reform commenced a liberal shift on the policies designed to protect farmers across Europe. The CAP Health Check of 2008 and the 2013 CAP Reform confirmed this change, adopting measures including the further decoupling of production, the abolishment of set-aside and the phasing-out of milk quotas. It is therefore expected that price transmission has been affected radically. This study investigates the price transmission mechanism along the European food supply chain, based on an asymmetric panel vector error correction model (VECM). Panel data on agricultural commodity (farmer), producer (processor) and consumer (retailer) prices from nineteen European countries are considered. The sample is split into two sub-periods, before and after the CAP Health Check, to examine how the price transmission mechanism has been affected. Cointegration is confirmed among the price series through the Pedroni tests and the long-run relationship is obtained with two estimation methods (i. e. fully modified OLS and dynamic OLS). Prior to the CAP Health Check, positive asymmetry is detected from farmer to processor and from processor to retailer. However, after the CAP Health Check price transmission becomes symmetric, thus suggesting that decreased support has resulted in a more efficient price transmission mechanism.","PeriodicalId":52541,"journal":{"name":"Journal of Agricultural and Food Industrial Organization","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/jafio-2018-0002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47072477","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}
Abstract This article investigates the substitution between online advertising (ONLA) and offline advertising (OFFLA) as well as the impact of adopting ONLA on the total cost of advertising. We estimate an advertising translog cost function at the product-brand level, using monthly observations between 2005 and 2011 for each of three industries: beer, ready-to-eat cereals, and carbonated soft drinks. Although in all three industries we find that traditional media (TV and print) advertisements are close substitutes, we also find that ONLA is a complement to, rather than a substitute for, both TV and print media advertising. This may be explained by ONLA’s targeting younger market segments and acting as a reinforcement of TV and print media advertising exposure. Further results show that the adoption of ONLA has lowered the cost of advertising for achieving a sales target and that its complementarity effect is weakening over time.
{"title":"Are Online and Offline Advertising Substitutes or Complements? Evidence from U.S. Food Industries","authors":"Xi He, R. Lopez, Yizao Liu","doi":"10.1515/jafio-2017-0031","DOIUrl":"https://doi.org/10.1515/jafio-2017-0031","url":null,"abstract":"Abstract This article investigates the substitution between online advertising (ONLA) and offline advertising (OFFLA) as well as the impact of adopting ONLA on the total cost of advertising. We estimate an advertising translog cost function at the product-brand level, using monthly observations between 2005 and 2011 for each of three industries: beer, ready-to-eat cereals, and carbonated soft drinks. Although in all three industries we find that traditional media (TV and print) advertisements are close substitutes, we also find that ONLA is a complement to, rather than a substitute for, both TV and print media advertising. This may be explained by ONLA’s targeting younger market segments and acting as a reinforcement of TV and print media advertising exposure. Further results show that the adoption of ONLA has lowered the cost of advertising for achieving a sales target and that its complementarity effect is weakening over time.","PeriodicalId":52541,"journal":{"name":"Journal of Agricultural and Food Industrial Organization","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/jafio-2017-0031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43227337","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}
Abstract Current trends in the structure of hog production in the U.S. are toward facilities that are not only larger, but also more likely to be specialized, carrying out only some of the vertically linked phases of production in the same facility. This paper investigates the cost efficiency incentives for these changes by estimating a multistage cost function for hog production. Data are from the Hog Production Practices and Costs portion of the USDA’s 2004 Agricultural Resource Management Survey.
{"title":"A Re-Examination of Multistage Economies in Hog Farming","authors":"Joshua D. Parcel, John R. Schroeter, A. Azzam","doi":"10.1515/jafio-2017-0033","DOIUrl":"https://doi.org/10.1515/jafio-2017-0033","url":null,"abstract":"Abstract Current trends in the structure of hog production in the U.S. are toward facilities that are not only larger, but also more likely to be specialized, carrying out only some of the vertically linked phases of production in the same facility. This paper investigates the cost efficiency incentives for these changes by estimating a multistage cost function for hog production. Data are from the Hog Production Practices and Costs portion of the USDA’s 2004 Agricultural Resource Management Survey.","PeriodicalId":52541,"journal":{"name":"Journal of Agricultural and Food Industrial Organization","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/jafio-2017-0033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45240321","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}
Abstract In Hotelling’s linear town model characteristics are implicitly assumed to be related in such a way that preferences for them can be mapped into a one-dimensional town. This results in perfectly correlated willingness to pay levels. Many differentiated products, however, embody characteristics that are functionally at least somewhat unrelated to other characteristics. This paper makes the implicit assumption of perfectly correlated preferences in the original Hotelling model explicit, and examine the implications of this assumption for the economics of competition. We develop a simple theoretical model to show that shape of the demand curve for differentiated products depends on distribution of consumers’ preferences, which is determined by the nature of the relationship between the corresponding characteristics. Misrepresentation of correlated preferences in differentiated product models impacts demand elasticity and can result in unreliable outcomes. This issue is particularly important in agricultural and food markets where many factors such as expectations about weather and information on social media can impact consumer ranking of one product versus another in ways that are not fully observable or measurable by the researcher.
{"title":"Non-Linear Demand in a Linear Town","authors":"M. Torshizi, M. Fulton, R. Gray","doi":"10.1515/jafio-2017-0019","DOIUrl":"https://doi.org/10.1515/jafio-2017-0019","url":null,"abstract":"Abstract In Hotelling’s linear town model characteristics are implicitly assumed to be related in such a way that preferences for them can be mapped into a one-dimensional town. This results in perfectly correlated willingness to pay levels. Many differentiated products, however, embody characteristics that are functionally at least somewhat unrelated to other characteristics. This paper makes the implicit assumption of perfectly correlated preferences in the original Hotelling model explicit, and examine the implications of this assumption for the economics of competition. We develop a simple theoretical model to show that shape of the demand curve for differentiated products depends on distribution of consumers’ preferences, which is determined by the nature of the relationship between the corresponding characteristics. Misrepresentation of correlated preferences in differentiated product models impacts demand elasticity and can result in unreliable outcomes. This issue is particularly important in agricultural and food markets where many factors such as expectations about weather and information on social media can impact consumer ranking of one product versus another in ways that are not fully observable or measurable by the researcher.","PeriodicalId":52541,"journal":{"name":"Journal of Agricultural and Food Industrial Organization","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/jafio-2017-0019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66825864","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}
Abstract Food safety enjoys sustained attention among the scientific community, policymakers, and the general public due to health impacts. However, pursuing appropriate regulations for pervasive food contaminants is a challenging policy issue, particularly for naturally-occurring food toxins such as aflatoxins and other mycotoxins. This paper explores consumer preferences for quality aflatoxin-free peanuts, and how food safety concerns may impact willingness to pay more for safer foods. Incorporating ‘risky’ foods into random utility-maximization framework, we analyze contingent valuation survey data on Ghana. Model and survey results show consumers in Ghana approve of food aflatoxin regulations, and are prepared to pay price premiums as incentives to ensure supply of quality peanuts. Findings reveal that consumers prioritize food safety above prices in market decisions. People prefer introduction of aflatoxin regulations that would guarantee good health; useful information for policy makers in Ghana, Africa, and rest of the developing world.
{"title":"Aflatoxins and Health Considerations in Consumer Food Choices in Ghana","authors":"M. Agyekum, C. Jolly, Henry Thompson","doi":"10.1515/JAFIO-2017-0015","DOIUrl":"https://doi.org/10.1515/JAFIO-2017-0015","url":null,"abstract":"Abstract Food safety enjoys sustained attention among the scientific community, policymakers, and the general public due to health impacts. However, pursuing appropriate regulations for pervasive food contaminants is a challenging policy issue, particularly for naturally-occurring food toxins such as aflatoxins and other mycotoxins. This paper explores consumer preferences for quality aflatoxin-free peanuts, and how food safety concerns may impact willingness to pay more for safer foods. Incorporating ‘risky’ foods into random utility-maximization framework, we analyze contingent valuation survey data on Ghana. Model and survey results show consumers in Ghana approve of food aflatoxin regulations, and are prepared to pay price premiums as incentives to ensure supply of quality peanuts. Findings reveal that consumers prioritize food safety above prices in market decisions. People prefer introduction of aflatoxin regulations that would guarantee good health; useful information for policy makers in Ghana, Africa, and rest of the developing world.","PeriodicalId":52541,"journal":{"name":"Journal of Agricultural and Food Industrial Organization","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/JAFIO-2017-0015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44596566","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 provides estimates of elasticities of substitution between domestic and imported goods for 40 4-digit S.I.C. food manufacturing industries and explains the inter-industry differences among these coefficients in terms of industry sectoral characteristics. The results show that there is a wide range of variation among such elasticities and that the intensity of each industry’s percentage of output sold to final consumers, foreign direct investment, expenditures on advertising and the existence of import quotas affect the degree of substitutability between domestic and foreign goods in the face of a relative price change.
{"title":"Estimates and Determinants of Armington Elasticities for the U.S. Food Industry","authors":"L. Elena, Pagoulatos Emilio","doi":"10.1515/JAFIO-2017-0040","DOIUrl":"https://doi.org/10.1515/JAFIO-2017-0040","url":null,"abstract":"This paper provides estimates of elasticities of substitution between domestic and imported goods for 40 4-digit S.I.C. food manufacturing industries and explains the inter-industry differences among these coefficients in terms of industry sectoral characteristics. The results show that there is a wide range of variation among such elasticities and that the intensity of each industry’s percentage of output sold to final consumers, foreign direct investment, expenditures on advertising and the existence of import quotas affect the degree of substitutability between domestic and foreign goods in the face of a relative price change.","PeriodicalId":52541,"journal":{"name":"Journal of Agricultural and Food Industrial Organization","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/JAFIO-2017-0040","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46592558","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}
Abstract This paper examines the impact of a food contamination scare in the dairy sector on dairy exports. We investigate this question in the context of the 2013 Whey Protein Concentrate contamination incident in New Zealand. We assess the impact of this incident on dairy exports using synthetic control methods. A synthetic counterfactual scenario where the incident did not occur is developed using weighted information from other countries unaffected by the scare. We find that there was an initial negative shock to the exports of products that were thought to have been contaminated, but that there were no significant sustained impacts on other dairy products. The affected products made up only a small proportion of New Zealand dairy exports, with the vast majority of dairy exports being unaffected. Infant formula exports appear to have recovered more than a year after the scare. However, whey product exports (the contaminated product) remain lower than they otherwise would have been.
{"title":"The Trade Impacts of a Food Scare: The Fonterra Contamination Incident","authors":"Katarina Stojkov, Ilan Noy, Yiğit Sağlam","doi":"10.1515/JAFIO-2016-0031","DOIUrl":"https://doi.org/10.1515/JAFIO-2016-0031","url":null,"abstract":"Abstract This paper examines the impact of a food contamination scare in the dairy sector on dairy exports. We investigate this question in the context of the 2013 Whey Protein Concentrate contamination incident in New Zealand. We assess the impact of this incident on dairy exports using synthetic control methods. A synthetic counterfactual scenario where the incident did not occur is developed using weighted information from other countries unaffected by the scare. We find that there was an initial negative shock to the exports of products that were thought to have been contaminated, but that there were no significant sustained impacts on other dairy products. The affected products made up only a small proportion of New Zealand dairy exports, with the vast majority of dairy exports being unaffected. Infant formula exports appear to have recovered more than a year after the scare. However, whey product exports (the contaminated product) remain lower than they otherwise would have been.","PeriodicalId":52541,"journal":{"name":"Journal of Agricultural and Food Industrial Organization","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/JAFIO-2016-0031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42351026","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}
Abstract Russia has emerged as a major wheat exporter since the beginning of the 2000s, and today, it possesses high market shares in several wheat-importing countries in the Middle East and North African region. This has raised concerns that Russia might abuse its dominant market position by pricing above marginal cost. Using a novel dataset with weekly information on Russian wheat exports, we apply the residual demand elasticity method to analyze the pricing behavior of Russia in its two most important export markets, i. e. Egypt and Turkey. Our estimation results reveal that Russia behaves competitively in Egypt while it exerts market power in Turkey with an estimated mark-up of 13.5 %.
{"title":"Russian Market Power in International Wheat Exports: Evidence from a Residual Demand Elasticity Analysis","authors":"Kerstin Marit Uhl, O. Perekhozhuk, T. Glauben","doi":"10.1515/jafio-2016-0026","DOIUrl":"https://doi.org/10.1515/jafio-2016-0026","url":null,"abstract":"Abstract Russia has emerged as a major wheat exporter since the beginning of the 2000s, and today, it possesses high market shares in several wheat-importing countries in the Middle East and North African region. This has raised concerns that Russia might abuse its dominant market position by pricing above marginal cost. Using a novel dataset with weekly information on Russian wheat exports, we apply the residual demand elasticity method to analyze the pricing behavior of Russia in its two most important export markets, i. e. Egypt and Turkey. Our estimation results reveal that Russia behaves competitively in Egypt while it exerts market power in Turkey with an estimated mark-up of 13.5 %.","PeriodicalId":52541,"journal":{"name":"Journal of Agricultural and Food Industrial Organization","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/jafio-2016-0026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41718057","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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