We study welfare effects of horizontal mergers under a successive oligopoly model and find that downstream mergers can increase welfare if they reduce input prices. The lower input price shifts some input production from cost-inefficient upstream firms to cost-efficient ones. Also, the lower input price makes upstream entry less attractive, reduces the number of upstream entrants, and decreases their average costs in the presence of fixed entry costs. We identity necessary and sufficient conditions for a reduction in input prices and welfare-improving horizontal mergers under a general demand function. Qualitative nature of our findings remains unchanged for upstream mergers.
{"title":"Horizontal Mergers in the Presence of Vertical Relationships","authors":"A. Ghosh, H. Morita, Chengsi Wang","doi":"10.2139/ssrn.2529687","DOIUrl":"https://doi.org/10.2139/ssrn.2529687","url":null,"abstract":"We study welfare effects of horizontal mergers under a successive oligopoly model and find that downstream mergers can increase welfare if they reduce input prices. The lower input price shifts some input production from cost-inefficient upstream firms to cost-efficient ones. Also, the lower input price makes upstream entry less attractive, reduces the number of upstream entrants, and decreases their average costs in the presence of fixed entry costs. We identity necessary and sufficient conditions for a reduction in input prices and welfare-improving horizontal mergers under a general demand function. Qualitative nature of our findings remains unchanged for upstream mergers.","PeriodicalId":249710,"journal":{"name":"ERN: Theory & Evidence on Vertical & Horizontal Integration (Topic)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123155113","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 the systemic risk effects of bank mergers to test the “concentration-fragility” hypothesis. We use the marginal expected shortfall as well as the lower tail dependence between a bank’s stock returns and a relevant bank sector index to capture the merger-related change in an acquirer’s contribution to systemic risk. In our empirical analysis of a dataset of international domestic and cross-border mergers, we find clear evidence for a significant increase in the merging banks’, the combined banks’ as well as their competitors’ contribution to systemic risk following mergers, thus confirming the “concentration-fragility” hypothesis.
{"title":"Systemic Risk and Bank Consolidation: International Evidence","authors":"Gregor N. F. Weiß, S. Neumann, Denefa Bostandzic","doi":"10.2139/ssrn.1914352","DOIUrl":"https://doi.org/10.2139/ssrn.1914352","url":null,"abstract":"This paper analyzes the systemic risk effects of bank mergers to test the “concentration-fragility” hypothesis. We use the marginal expected shortfall as well as the lower tail dependence between a bank’s stock returns and a relevant bank sector index to capture the merger-related change in an acquirer’s contribution to systemic risk. In our empirical analysis of a dataset of international domestic and cross-border mergers, we find clear evidence for a significant increase in the merging banks’, the combined banks’ as well as their competitors’ contribution to systemic risk following mergers, thus confirming the “concentration-fragility” hypothesis.","PeriodicalId":249710,"journal":{"name":"ERN: Theory & Evidence on Vertical & Horizontal Integration (Topic)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122224701","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 regulation of vertical relationships between firms is the subject of persistent legal and academic controversy. The literature studying vertical trade relationships seems to assume that an upstream monopolist prefers downstream competition over exclusive distribution arrangements. We derive precise conditions for when an upstream monopolist prefers competing distribution systems over exclusive distribution in the downstream market. We also show that the welfare effects of downstream competition are ambiguous. A downstream oligopoly may have negative welfare properties compared to a downstream monopoly.
{"title":"On the Welfare Effects of Exclusive Distribution Arrangements","authors":"J. Eichberger, Frank Mueller‐Langer","doi":"10.2139/ssrn.2069860","DOIUrl":"https://doi.org/10.2139/ssrn.2069860","url":null,"abstract":"The regulation of vertical relationships between firms is the subject of persistent legal and academic controversy. The literature studying vertical trade relationships seems to assume that an upstream monopolist prefers downstream competition over exclusive distribution arrangements. We derive precise conditions for when an upstream monopolist prefers competing distribution systems over exclusive distribution in the downstream market. We also show that the welfare effects of downstream competition are ambiguous. A downstream oligopoly may have negative welfare properties compared to a downstream monopoly.","PeriodicalId":249710,"journal":{"name":"ERN: Theory & Evidence on Vertical & Horizontal Integration (Topic)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126496235","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 literature on vertical integration in markets with regulated upstream prices suggests that the integrated upstream firm might engage in non-price discrimination. Several studies provide policy recommendations derived either from case study approaches or based on theoretical modeling which addresses the unbundling issue. In this study we analyze the impact of vertical integration of retail incumbent and network operator on retail prices and upstream charges. As the vertical structure is heterogeneous across the 850 German electricity submarkets for residential customers (there exist legally unbundled, vertically integrated or fully separated firms), we use firm level data to analyze the effects of different vertical structures and regulation schemes on retail electricity prices. We find significantly higher prices in markets with vertically integrated firms compared to markets with fully separated firms. This finding could indicate non-price discrimination. Furthermore, we find no evidence that legal unbundling eliminates the incentives for non-price discrimination because the prices do not differ from prices in markets under vertical integration.
{"title":"Vertical Integration, Separation and Non-Price Discrimination: An Empirical Analysis of German Electricity Markets for Residential Customers","authors":"V. Nikogosian, Tobias Veith","doi":"10.2139/ssrn.1991819","DOIUrl":"https://doi.org/10.2139/ssrn.1991819","url":null,"abstract":"The literature on vertical integration in markets with regulated upstream prices suggests that the integrated upstream firm might engage in non-price discrimination. Several studies provide policy recommendations derived either from case study approaches or based on theoretical modeling which addresses the unbundling issue. In this study we analyze the impact of vertical integration of retail incumbent and network operator on retail prices and upstream charges. As the vertical structure is heterogeneous across the 850 German electricity submarkets for residential customers (there exist legally unbundled, vertically integrated or fully separated firms), we use firm level data to analyze the effects of different vertical structures and regulation schemes on retail electricity prices. We find significantly higher prices in markets with vertically integrated firms compared to markets with fully separated firms. This finding could indicate non-price discrimination. Furthermore, we find no evidence that legal unbundling eliminates the incentives for non-price discrimination because the prices do not differ from prices in markets under vertical integration.","PeriodicalId":249710,"journal":{"name":"ERN: Theory & Evidence on Vertical & Horizontal Integration (Topic)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130253082","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}
We present evidence that some firms pursue mergers with an objective of acquiring and retaining the target firm’s employees. We identify such target firms by the language used to describe employees in their 10-K statements, focusing on references to “skilled” employees. We find a positive correlation between the use of the word “skilled” and post-merger employment outcomes. Moreover, we find that it is the target employees most valuable to the firm that are relatively more likely to be retained following an acquiring-labor-motivated acquisition. Acquirers appear to retain the high value employees in acquiring-labor-motivated acquisitions by providing these workers with relatively greater wage increases.
{"title":"Acquiring Labor","authors":"P. Ouimet, Rebecca Zarutskie","doi":"10.2139/ssrn.1571891","DOIUrl":"https://doi.org/10.2139/ssrn.1571891","url":null,"abstract":"We present evidence that some firms pursue mergers with an objective of acquiring and retaining the target firm’s employees. We identify such target firms by the language used to describe employees in their 10-K statements, focusing on references to “skilled” employees. We find a positive correlation between the use of the word “skilled” and post-merger employment outcomes. Moreover, we find that it is the target employees most valuable to the firm that are relatively more likely to be retained following an acquiring-labor-motivated acquisition. Acquirers appear to retain the high value employees in acquiring-labor-motivated acquisitions by providing these workers with relatively greater wage increases.","PeriodicalId":249710,"journal":{"name":"ERN: Theory & Evidence on Vertical & Horizontal Integration (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130893306","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}
We investigate the impact of cross-border takeovers on target banks’ profitability, efficiency, and market share in Ukraine, an exemplar of a country with poor institutional quality. We rely on a combination of propensity score matching with the difference-in-difference methodology, and our main contribution lies in an additional sensitivity analysis that checks for the presence of temporary unobservable factors. Our results show that foreign investors have acquired Ukrainian banks with average efficiency and profitability, and that these indicators did not change significantly post-takeover. By contrast, foreign banks have targeted mainly large banks, and during the first two years following acquisition the targets’ loan market share and size even increased, whereas funding costs decreased effects that are robust for the presence of temporary unobservable factors. In line with Lanine and Vander Vennet (2007), we thus find that foreign banks are interested in increasing their market share rather than exporting their efficiency.
{"title":"Cross-Border Takeovers and Efficiency of Acquired Banks in Transition Economies: An Observational Study on Ukraine","authors":"Muzaffarjon Ahunov, L. Van Hove, M. Jegers","doi":"10.2139/ssrn.1935497","DOIUrl":"https://doi.org/10.2139/ssrn.1935497","url":null,"abstract":"We investigate the impact of cross-border takeovers on target banks’ profitability, efficiency, and market share in Ukraine, an exemplar of a country with poor institutional quality. We rely on a combination of propensity score matching with the difference-in-difference methodology, and our main contribution lies in an additional sensitivity analysis that checks for the presence of temporary unobservable factors. Our results show that foreign investors have acquired Ukrainian banks with average efficiency and profitability, and that these indicators did not change significantly post-takeover. By contrast, foreign banks have targeted mainly large banks, and during the first two years following acquisition the targets’ loan market share and size even increased, whereas funding costs decreased effects that are robust for the presence of temporary unobservable factors. In line with Lanine and Vander Vennet (2007), we thus find that foreign banks are interested in increasing their market share rather than exporting their efficiency.","PeriodicalId":249710,"journal":{"name":"ERN: Theory & Evidence on Vertical & Horizontal Integration (Topic)","volume":"51 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125759212","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}
Pub Date : 2011-06-01DOI: 10.1111/j.1467-9701.2011.01345.x
R. Bandick
This paper studies the effect of foreign acquisition on wages and total factor productivity (TFP) in the years following a takeover by using unique detailed firm-level data for Sweden for the period 1993-2002. The paper takes particular account of the potential endogeneity of the acquisition decision (for example due to “cherry picking”) by implementing an instrumental variable approach and propensity score matching with difference-in-difference estimation technique. Moreover, in line with recent literature on firm heterogeneity in international trade, this paper allows for the acquisition effect to differ depending on whether the targeted firms were domestic multinational or non-multinationals before the foreign takeover. This paper also allows for the acquisition effect to differ depending on whether the acquisition is horizontal or vertical. The result shows that foreign acquisition has no effects on overall, skilled or less-skilled wage growth neither in targeted Swedish MNEs nor in targeted Swedish non-MNEs and neither if the acquisition was motivated by vertical or horizontal motives. However, the results indicate that both targeted Swedish MNEs and non- MNEs have better growth in TFP after vertical foreign acquisition only but no such impact from horizontal foreign acquisition
{"title":"Foreign Acquisition, Wages and Productivity","authors":"R. Bandick","doi":"10.1111/j.1467-9701.2011.01345.x","DOIUrl":"https://doi.org/10.1111/j.1467-9701.2011.01345.x","url":null,"abstract":"This paper studies the effect of foreign acquisition on wages and total factor productivity (TFP) in the years following a takeover by using unique detailed firm-level data for Sweden for the period 1993-2002. The paper takes particular account of the potential endogeneity of the acquisition decision (for example due to “cherry picking”) by implementing an instrumental variable approach and propensity score matching with difference-in-difference estimation technique. Moreover, in line with recent literature on firm heterogeneity in international trade, this paper allows for the acquisition effect to differ depending on whether the targeted firms were domestic multinational or non-multinationals before the foreign takeover. This paper also allows for the acquisition effect to differ depending on whether the acquisition is horizontal or vertical. The result shows that foreign acquisition has no effects on overall, skilled or less-skilled wage growth neither in targeted Swedish MNEs nor in targeted Swedish non-MNEs and neither if the acquisition was motivated by vertical or horizontal motives. However, the results indicate that both targeted Swedish MNEs and non- MNEs have better growth in TFP after vertical foreign acquisition only but no such impact from horizontal foreign acquisition","PeriodicalId":249710,"journal":{"name":"ERN: Theory & Evidence on Vertical & Horizontal Integration (Topic)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129216898","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}
Using a database of more than 2,000 international bank M&A deals completed between 1990 and 2007 and the unique bank regulation data collected by Barth, Caprio, and Levine (2006), we analyze the effects of bank regulations on bank's cross-border M&As around the world. Results suggest that banks have strong incentives to expand into lightly regulated countries, indicating that banks' international footing provides them a natural way of regulatory arbitrage. Also we find that the takeover premium is increasing if the target bank is located in a country with less stringent capital requirement, more independence of supervisory authority, and lower standards of disclosure requirement. Given that regulators are concerned about the shareholders of their domestic banks, they may lower their bank regulation standards in order to provide domestic banks with an advantage over foreign banks and increase their profitability. Therefore, our paper provides an explanation of "competition in laxity" of bank regulations in individual countries. Further, we provide evidence that there is no significant increase in the financial performance in the combined banks, partly due to the motivation of regulatory arbitrage of bank managers in cross-board M&As.
{"title":"Regulatory Arbitrage: Evidence from Bank Cross-Border M&As","authors":"Huiyan Dong, F. Song, Libin Tao","doi":"10.2139/ssrn.1849723","DOIUrl":"https://doi.org/10.2139/ssrn.1849723","url":null,"abstract":"Using a database of more than 2,000 international bank M&A deals completed between 1990 and 2007 and the unique bank regulation data collected by Barth, Caprio, and Levine (2006), we analyze the effects of bank regulations on bank's cross-border M&As around the world. Results suggest that banks have strong incentives to expand into lightly regulated countries, indicating that banks' international footing provides them a natural way of regulatory arbitrage. Also we find that the takeover premium is increasing if the target bank is located in a country with less stringent capital requirement, more independence of supervisory authority, and lower standards of disclosure requirement. Given that regulators are concerned about the shareholders of their domestic banks, they may lower their bank regulation standards in order to provide domestic banks with an advantage over foreign banks and increase their profitability. Therefore, our paper provides an explanation of \"competition in laxity\" of bank regulations in individual countries. Further, we provide evidence that there is no significant increase in the financial performance in the combined banks, partly due to the motivation of regulatory arbitrage of bank managers in cross-board M&As.","PeriodicalId":249710,"journal":{"name":"ERN: Theory & Evidence on Vertical & Horizontal Integration (Topic)","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133707535","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}
Purpose - This paper investigates the Jensen's free cash flow (FCF) hypothesis in the context of UK cash acquisitions. Under this hypothesis, financial slack induces mangers to acquire targets for cash if such behaviour generates either pecuniary or non-pecuniary rewards for them, giving rise to a potential agency problem around cash takeovers. We argue that the stronger position of shareholders, as opposed to firm managers, in the UK should help in constraining such potential agency problems around such mergers. Compared to the USA, position, this should make the FCF hypothesis less relevant in the UK. Design/methodology/approach - This paper uses short-run announcement period returns and long-run calendar-time returns in testing our hypotheses. Findings - This paper shows that low leverage and high FCF may be advantageous provided shareholder monitoring is adequate. By analysing both announcement period and long-term returns, we show that acquirers with high levels of FCF are superior performers, and that any long-run under-performance of cash acquirers appears to be associated with low cash resources and low institutional ownership. Research limitations/implications - Inevitably, long-run returns measurement is contentious, although we present results from alternative models to mitigate this. Limitations are necessarily imposed by the sample size, meaning that multi-way partitioning of the data is not feasible. Practical implications - The practical implications are that the UK regulatory and institutional ownership regime may actually protect the interests of shareholders and mitigate agency problems. Originality/value - As far as we are aware, this is the first paper to systematically test FCF, leverage and institutional ownership effects in the context of UK cash acquisitions.
{"title":"Cash Acquirers: Can Free Cash Flow, Debt and Institutional Ownership Explain Long Run Performance?","authors":"A. Gregory, Yuan-Hsin Wang","doi":"10.2139/ssrn.1793094","DOIUrl":"https://doi.org/10.2139/ssrn.1793094","url":null,"abstract":"Purpose - This paper investigates the Jensen's free cash flow (FCF) hypothesis in the context of UK cash acquisitions. Under this hypothesis, financial slack induces mangers to acquire targets for cash if such behaviour generates either pecuniary or non-pecuniary rewards for them, giving rise to a potential agency problem around cash takeovers. We argue that the stronger position of shareholders, as opposed to firm managers, in the UK should help in constraining such potential agency problems around such mergers. Compared to the USA, position, this should make the FCF hypothesis less relevant in the UK. Design/methodology/approach - This paper uses short-run announcement period returns and long-run calendar-time returns in testing our hypotheses. Findings - This paper shows that low leverage and high FCF may be advantageous provided shareholder monitoring is adequate. By analysing both announcement period and long-term returns, we show that acquirers with high levels of FCF are superior performers, and that any long-run under-performance of cash acquirers appears to be associated with low cash resources and low institutional ownership. Research limitations/implications - Inevitably, long-run returns measurement is contentious, although we present results from alternative models to mitigate this. Limitations are necessarily imposed by the sample size, meaning that multi-way partitioning of the data is not feasible. Practical implications - The practical implications are that the UK regulatory and institutional ownership regime may actually protect the interests of shareholders and mitigate agency problems. Originality/value - As far as we are aware, this is the first paper to systematically test FCF, leverage and institutional ownership effects in the context of UK cash acquisitions.","PeriodicalId":249710,"journal":{"name":"ERN: Theory & Evidence on Vertical & Horizontal Integration (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126130214","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}
We analyze health care option demand markets with vertical restraints divided along two dimensions: naked and conditional exclusion, and vertical integration; applicable to the upstream, the downstream, and both markets. Our unified framework includes forward and backward integration, and joint ventures. We show that conditional exclusion has the same bargaining effects as vertical integration, but without the joint profit optimization. There are no individual incentives for exclusive dealing, but hospital-insurer pairs can find it jointly profitable to apply downstream vertical restraints on third parties. Outright downstream monopolization arises only when consumers have strong enough preferences for free provider choice.
{"title":"Vertical Restraints in Health Care Markets","authors":"R. Halbersma, K. Katona","doi":"10.2139/ssrn.1748519","DOIUrl":"https://doi.org/10.2139/ssrn.1748519","url":null,"abstract":"We analyze health care option demand markets with vertical restraints divided along two dimensions: naked and conditional exclusion, and vertical integration; applicable to the upstream, the downstream, and both markets. Our unified framework includes forward and backward integration, and joint ventures. We show that conditional exclusion has the same bargaining effects as vertical integration, but without the joint profit optimization. There are no individual incentives for exclusive dealing, but hospital-insurer pairs can find it jointly profitable to apply downstream vertical restraints on third parties. Outright downstream monopolization arises only when consumers have strong enough preferences for free provider choice.","PeriodicalId":249710,"journal":{"name":"ERN: Theory & Evidence on Vertical & Horizontal Integration (Topic)","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128802192","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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