In this paper, we reconcile the disparity between regional and national level estimates of the effect of immigration on native earnings. The reconciliation derives from the fact that existing national level studies fail to adequately control for changes in other determinants of the wage structure that correspond closely with the skill distribution of immigrant shocks. We focus specifically on the effect of accounting for incarceration trends. Over the past thirty years, an increasing proportion of low skilled native workers have served time in prison, a development that has arguably harmed their employment prospects. We show that the fraction of a given education-experience group that is immigrant is strongly correlated with the fraction of native born workers in the demographic group that is institutionalized. Holding constant incarceration trends considerably diminishes the estimated magnitude of the reduced-form relationship between native labor market outcomes and the fraction in their skill cell that is immigrant.An alternative interpretation of these findings offered by Borjas, Grogger, and Hansen (2006) is that immigration-induced wage declines have pushed more men into criminal activity which, in turn, has increased the incarceration rate. The authors present a model whereby the reduced form effect of immigration on incarceration reflects the product of (1) the effect of immigration on wages and (2) the elasticity of labor demand in the crime sector. The latter elasticity gauges the extent to which the local crime market is able to absorb additional offenders as the quality of legitimate work opportunities (as measured by wages) diminishes. While national level correlations presented by the authors are consistent with this interpretation, we show that the state level results are not. Despite a sizable and statistically significant negative reduced-form effect of immigrant penetration on wages in state-level panel regressions, there is no statistically significant relationship between state-level immigrant shocks and state-level incarceration rates - i.e., despite an identifiable dose to state-level wages, there is no incarceration response. Estimates of the elasticity of demand in the criminal sector using both the original state-level estimates presented in Borjas, Grogger, and Hansen (2006) as well as our replication and simple alternative specification of these regressions are essentially zero. Thus, we conclude that immigration has had no impact on criminal activity among natives operating through labor market competition.
{"title":"Reconciling National and Regional Estimates of the Effect of Immigration on U.S. Labor Markets: The Confounding Effects of Native Male Incarceration Trends","authors":"S. Raphael, L. Ronconi","doi":"10.2139/ssrn.1248290","DOIUrl":"https://doi.org/10.2139/ssrn.1248290","url":null,"abstract":"In this paper, we reconcile the disparity between regional and national level estimates of the effect of immigration on native earnings. The reconciliation derives from the fact that existing national level studies fail to adequately control for changes in other determinants of the wage structure that correspond closely with the skill distribution of immigrant shocks. We focus specifically on the effect of accounting for incarceration trends. Over the past thirty years, an increasing proportion of low skilled native workers have served time in prison, a development that has arguably harmed their employment prospects. We show that the fraction of a given education-experience group that is immigrant is strongly correlated with the fraction of native born workers in the demographic group that is institutionalized. Holding constant incarceration trends considerably diminishes the estimated magnitude of the reduced-form relationship between native labor market outcomes and the fraction in their skill cell that is immigrant.An alternative interpretation of these findings offered by Borjas, Grogger, and Hansen (2006) is that immigration-induced wage declines have pushed more men into criminal activity which, in turn, has increased the incarceration rate. The authors present a model whereby the reduced form effect of immigration on incarceration reflects the product of (1) the effect of immigration on wages and (2) the elasticity of labor demand in the crime sector. The latter elasticity gauges the extent to which the local crime market is able to absorb additional offenders as the quality of legitimate work opportunities (as measured by wages) diminishes. While national level correlations presented by the authors are consistent with this interpretation, we show that the state level results are not. Despite a sizable and statistically significant negative reduced-form effect of immigrant penetration on wages in state-level panel regressions, there is no statistically significant relationship between state-level immigrant shocks and state-level incarceration rates - i.e., despite an identifiable dose to state-level wages, there is no incarceration response. Estimates of the elasticity of demand in the criminal sector using both the original state-level estimates presented in Borjas, Grogger, and Hansen (2006) as well as our replication and simple alternative specification of these regressions are essentially zero. Thus, we conclude that immigration has had no impact on criminal activity among natives operating through labor market competition.","PeriodicalId":106212,"journal":{"name":"Labor: Demographics & Economics of the Family","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124574151","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 summarizes the background, type, logic, and working procedure of the statistical matching used in the Levy Institute Measure of Economic Wellbeing (LIMEW) project to combine the various data sets used to produce the synthetic data set with which the LIMEW is constructed. We use the match between the 2001 Survey of Consumer Finances and Annual Demographic Survey of Current Population Survey data sets to demonstrate the procedure and results of the matching. Challenges facing the use of this technique, such as the distribution of weights, are discussed in the conclusion.
{"title":"Statistical Matching Using Propensity Scores: Theory and Application to the Levy Institute Measure of Economic Well-Being","authors":"Hyunsub Kum, Thomas Masterson","doi":"10.2139/ssrn.1136363","DOIUrl":"https://doi.org/10.2139/ssrn.1136363","url":null,"abstract":"This paper summarizes the background, type, logic, and working procedure of the statistical matching used in the Levy Institute Measure of Economic Wellbeing (LIMEW) project to combine the various data sets used to produce the synthetic data set with which the LIMEW is constructed. We use the match between the 2001 Survey of Consumer Finances and Annual Demographic Survey of Current Population Survey data sets to demonstrate the procedure and results of the matching. Challenges facing the use of this technique, such as the distribution of weights, are discussed in the conclusion.","PeriodicalId":106212,"journal":{"name":"Labor: Demographics & Economics of the Family","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127809408","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}
Between 1961 and 2001, India's 0-6 sex ratio has steadily declined. Despite evidence to the contrary, there is a tendency to characterize this ratio in terms of a diagonal divide with low 0-6 sex ratios in northern and western India and for the most part, normal 0-6 sex ratios in eastern and southern India. While unexpectedly high rates of female infant mortality have been reported in Tamil Nadu, it is still regarded as lying outside the ambit of states with unusually low 0-6 sex ratios. Based on an analysis of temporal and spatial patterns in sex ratio at birth, infant mortality rates and under 5 mortality rates for Tamil Nadu, this paper traces the development of daughter deficit in the state and examines the validity of the diagonal divide in sex ratios across India. We find evidence of daughter deficit in more than half the state's districts with a majority of the shortfall arising before birth, potentially due to sex selective abortion as compared to after birth due to female infanticide. The evidence presented here, combined with earlier work on declining 0-6 sex ratios outside north-western India, suggests that the diagonal divide is no longer an appropriate distinction.
{"title":"Tamil Nadu and the Diagonal Divide in Sex Ratios","authors":"S. Srinivasan, A. Bedi","doi":"10.2139/ssrn.1128304","DOIUrl":"https://doi.org/10.2139/ssrn.1128304","url":null,"abstract":"Between 1961 and 2001, India's 0-6 sex ratio has steadily declined. Despite evidence to the contrary, there is a tendency to characterize this ratio in terms of a diagonal divide with low 0-6 sex ratios in northern and western India and for the most part, normal 0-6 sex ratios in eastern and southern India. While unexpectedly high rates of female infant mortality have been reported in Tamil Nadu, it is still regarded as lying outside the ambit of states with unusually low 0-6 sex ratios. Based on an analysis of temporal and spatial patterns in sex ratio at birth, infant mortality rates and under 5 mortality rates for Tamil Nadu, this paper traces the development of daughter deficit in the state and examines the validity of the diagonal divide in sex ratios across India. We find evidence of daughter deficit in more than half the state's districts with a majority of the shortfall arising before birth, potentially due to sex selective abortion as compared to after birth due to female infanticide. The evidence presented here, combined with earlier work on declining 0-6 sex ratios outside north-western India, suggests that the diagonal divide is no longer an appropriate distinction.","PeriodicalId":106212,"journal":{"name":"Labor: Demographics & Economics of the Family","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123416790","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 describes the methods of the second wave of the Spanish Survey of Household Finances (EFF2005), paying special attention to the innovations relative to the first wave. The EFF2005 was designed to give continuity to the information on household finances collected through the EFF2002. The EFF is the only statistical source in Spain that allows the linking of incomes, assets, debts, and consumption at the household level. A desirable characteristic present in both waves is the oversampling of wealthy households. This is achieved on the basis of the wealth tax through a blind system of collaboration between the National Statistics Institute and the Tax Office which preserves stringent tax confidentiality. An additional important characteristic of the EFF is that the second wave has a full panel component. Further, a refreshment sample by wealth stratum has been incorporated to preserve cross-sectional representativity and overall sample size.
{"title":"The Spanish Survey of Household Finances (EFF): Description and Methods of the 2005 Wave","authors":"O. Bover","doi":"10.2139/ssrn.1129146","DOIUrl":"https://doi.org/10.2139/ssrn.1129146","url":null,"abstract":"This paper describes the methods of the second wave of the Spanish Survey of Household Finances (EFF2005), paying special attention to the innovations relative to the first wave. The EFF2005 was designed to give continuity to the information on household finances collected through the EFF2002. The EFF is the only statistical source in Spain that allows the linking of incomes, assets, debts, and consumption at the household level. A desirable characteristic present in both waves is the oversampling of wealthy households. This is achieved on the basis of the wealth tax through a blind system of collaboration between the National Statistics Institute and the Tax Office which preserves stringent tax confidentiality. An additional important characteristic of the EFF is that the second wave has a full panel component. Further, a refreshment sample by wealth stratum has been incorporated to preserve cross-sectional representativity and overall sample size.","PeriodicalId":106212,"journal":{"name":"Labor: Demographics & Economics of the Family","volume":"1035 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116267146","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}
There are many possible pathways between parental education, income, and health, and between child health and education, but only some of them have been explored in the literature. This essay focuses on links between parental socioeconomic status (as measured by education, income, occupation, or in some cases area of residence) and child health, and between child health and adult education or income. Specifically, I ask two questions: What is the evidence regarding whether parental socioeconomic status affects child health? And, what is the evidence relating child health to future educational and labor market outcomes? I show that there is now strong evidence of both links, suggesting that health could play a role in the intergenerational transmission of economic status.
{"title":"Healthy, Wealthy, and Wise: Socioeconomic Status, Poor Health in Childhood, and Human Capital Development","authors":"J. Currie","doi":"10.1257/JEL.47.1.87","DOIUrl":"https://doi.org/10.1257/JEL.47.1.87","url":null,"abstract":"There are many possible pathways between parental education, income, and health, and between child health and education, but only some of them have been explored in the literature. This essay focuses on links between parental socioeconomic status (as measured by education, income, occupation, or in some cases area of residence) and child health, and between child health and adult education or income. Specifically, I ask two questions: What is the evidence regarding whether parental socioeconomic status affects child health? And, what is the evidence relating child health to future educational and labor market outcomes? I show that there is now strong evidence of both links, suggesting that health could play a role in the intergenerational transmission of economic status.","PeriodicalId":106212,"journal":{"name":"Labor: Demographics & Economics of the Family","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125677182","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}
Income inequality has been increasing in the United States over the past 25 years. Many argue that rising inequality is not a serious issue because income or social mobility reduces inequality and increases well-being. These observers point to studies showing considerable upward mobility. This study examines income mobility and its relation to income inequality. The results show that while there is considerable income mobility, it is generally not far - rags to riches success stories are fairly rare. Furthermore, income mobility has a disequalizing effect on annual income inequality, but has a small equalizing effect on inequality of longer-term incomes.
{"title":"U.S. Income Inequality and Income Mobility in the 1980s and 1990s","authors":"T. Hungerford","doi":"10.2139/ssrn.1133076","DOIUrl":"https://doi.org/10.2139/ssrn.1133076","url":null,"abstract":"Income inequality has been increasing in the United States over the past 25 years. Many argue that rising inequality is not a serious issue because income or social mobility reduces inequality and increases well-being. These observers point to studies showing considerable upward mobility. This study examines income mobility and its relation to income inequality. The results show that while there is considerable income mobility, it is generally not far - rags to riches success stories are fairly rare. Furthermore, income mobility has a disequalizing effect on annual income inequality, but has a small equalizing effect on inequality of longer-term incomes.","PeriodicalId":106212,"journal":{"name":"Labor: Demographics & Economics of the Family","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132486635","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 study compared intergenerational earnings mobility in Singapore and the United States by replicating the limitations in the Singapore National Youth Survey on the U.S. Panel Study of Income Dynamics. The mean estimated earnings elasticities are almost identical: 0.26 in Singapore and 0.27 in the United States. Transformed to 0.45 and 0.47 respectively to reflect permanent status, mobility in the two countries is moderately low compared internationally. The finding of similar mobility is not surprising given that the economic realities, welfare systems, education regimes, and labor structures in the two countries are similar. Policy makers face the daunting challenge of overcoming immobility and inequality while maintaining global competitiveness.
{"title":"Intergenerational Earnings Mobility in Singapore and the United States","authors":"Irene Y. H. Ng, Xiaoyi Shen, K. Ho","doi":"10.2139/ssrn.1127128","DOIUrl":"https://doi.org/10.2139/ssrn.1127128","url":null,"abstract":"This study compared intergenerational earnings mobility in Singapore and the United States by replicating the limitations in the Singapore National Youth Survey on the U.S. Panel Study of Income Dynamics. The mean estimated earnings elasticities are almost identical: 0.26 in Singapore and 0.27 in the United States. Transformed to 0.45 and 0.47 respectively to reflect permanent status, mobility in the two countries is moderately low compared internationally. The finding of similar mobility is not surprising given that the economic realities, welfare systems, education regimes, and labor structures in the two countries are similar. Policy makers face the daunting challenge of overcoming immobility and inequality while maintaining global competitiveness.","PeriodicalId":106212,"journal":{"name":"Labor: Demographics & Economics of the Family","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127970024","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 developed countries, obesity tends to be associated with worse labor market outcomes. One possible reason is that obesity leads to less human capital formation early in life. This paper investigates the association between obesity and the developmental functioning of children at younger ages (2-4 years) than ever previously examined. Data from the German Socio-Economic Panel Study are used to estimate models of developmental functioning in four critical areas (verbal skills, activities of daily living, motor skills, and social skills) as a function of various measures of weight (including BMI and obesity status) controlling for various child and family characteristics. The findings indicate that, among boys, obesity is a significant risk factor for lagged development in verbal skills, social skills, and activities of daily living. Among girls, weight generally does not have a statistically significant association with these developmental outcomes. Further investigations show that the correlations exist even for those preschool children who spend no time in day care, which implies that the correlation between obesity and developmental functioning cannot be due to discrimination by teachers, classmates, or even day care providers.
{"title":"Obesity and Developmental Functioning Among Children Aged 2-4 Years","authors":"J. Cawley, C. Spieß","doi":"10.2139/ssrn.1126593","DOIUrl":"https://doi.org/10.2139/ssrn.1126593","url":null,"abstract":"In developed countries, obesity tends to be associated with worse labor market outcomes. One possible reason is that obesity leads to less human capital formation early in life. This paper investigates the association between obesity and the developmental functioning of children at younger ages (2-4 years) than ever previously examined. Data from the German Socio-Economic Panel Study are used to estimate models of developmental functioning in four critical areas (verbal skills, activities of daily living, motor skills, and social skills) as a function of various measures of weight (including BMI and obesity status) controlling for various child and family characteristics. The findings indicate that, among boys, obesity is a significant risk factor for lagged development in verbal skills, social skills, and activities of daily living. Among girls, weight generally does not have a statistically significant association with these developmental outcomes. Further investigations show that the correlations exist even for those preschool children who spend no time in day care, which implies that the correlation between obesity and developmental functioning cannot be due to discrimination by teachers, classmates, or even day care providers.","PeriodicalId":106212,"journal":{"name":"Labor: Demographics & Economics of the Family","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126588404","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 presents results from a randomized field experiment to test for the importance of limited commitment (due to incomplete contract enforceability) in explaining intra-household risk sharing arrangements in Kenya. The experiment followed 142 daily income earners and their spouses for 8 weeks. Every week, each individual had a 50% chance of receiving a 150 Kenyan shilling (US $2) income shock (equivalent to about 1.5 days' income for men and 1 week's income for women). This paper has 2 main results. First, since the experimental payments are random, they allow for a direct test of allocative Pareto efficiency. I reject efficiency, as male private goods expenditures are sensitive to the receipt of the payment. Second, the experiment varied the level of intra-household correlation in the experimental payments between couples. I find that women send bigger transfers to their husbands when shocks are independent or negatively correlated, a result consistent with the presence of limited commitment. I find no difference in transfers for men, likely because the shocks were too small to cause the limited commitment constraint to bind for them.
{"title":"Limited Insurance within the Household: Evidence from a Field Experiment in Kenya","authors":"Jonathan Robinson","doi":"10.2139/ssrn.1282231","DOIUrl":"https://doi.org/10.2139/ssrn.1282231","url":null,"abstract":"This paper presents results from a randomized field experiment to test for the importance of limited commitment (due to incomplete contract enforceability) in explaining intra-household risk sharing arrangements in Kenya. The experiment followed 142 daily income earners and their spouses for 8 weeks. Every week, each individual had a 50% chance of receiving a 150 Kenyan shilling (US $2) income shock (equivalent to about 1.5 days' income for men and 1 week's income for women). This paper has 2 main results. First, since the experimental payments are random, they allow for a direct test of allocative Pareto efficiency. I reject efficiency, as male private goods expenditures are sensitive to the receipt of the payment. Second, the experiment varied the level of intra-household correlation in the experimental payments between couples. I find that women send bigger transfers to their husbands when shocks are independent or negatively correlated, a result consistent with the presence of limited commitment. I find no difference in transfers for men, likely because the shocks were too small to cause the limited commitment constraint to bind for them.","PeriodicalId":106212,"journal":{"name":"Labor: Demographics & Economics of the Family","volume":"62 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132434143","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 research design that traces siblings' preferences for postmaterialistic values in Germany over two decades, this paper provides new evidence on the origins of value preferences. Focusing on Inglehart's thesis of value change, we test the combined socialization and scarcity hypothesis against the social learning hypothesis, a prominent rival account of preadult value preference formation. Sibling estimates show that the shared preadult environment does indeed exert lasting effects on the permanent component of preferences for post-materialistic policies. In addition to weak effect of the shared experience of socioeconomic scarcity, we find that the intergenerational transmission of postmaterialism - which is disregarded by Inglehart's original thesis - plays a significant role in value preference acquisition. We discuss the implications of our individual-level findings for forecasts of aggregate-level trends in value change.
{"title":"The Preadult Origins of Post-Materialism: A Longitudinal Sibling Study","authors":"M. Kroh","doi":"10.2139/ssrn.1128182","DOIUrl":"https://doi.org/10.2139/ssrn.1128182","url":null,"abstract":"Using a research design that traces siblings' preferences for postmaterialistic values in Germany over two decades, this paper provides new evidence on the origins of value preferences. Focusing on Inglehart's thesis of value change, we test the combined socialization and scarcity hypothesis against the social learning hypothesis, a prominent rival account of preadult value preference formation. Sibling estimates show that the shared preadult environment does indeed exert lasting effects on the permanent component of preferences for post-materialistic policies. In addition to weak effect of the shared experience of socioeconomic scarcity, we find that the intergenerational transmission of postmaterialism - which is disregarded by Inglehart's original thesis - plays a significant role in value preference acquisition. We discuss the implications of our individual-level findings for forecasts of aggregate-level trends in value change.","PeriodicalId":106212,"journal":{"name":"Labor: Demographics & Economics of the Family","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115349425","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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