Climate change is expected to cause mass human migration, including immigration across international borders. This study quantitatively examines the linkages among variations in climate, agricultural yields, and people's migration responses by using an instrumental variables approach. Our method allows us to identify the relationship between crop yields and migration without explicitly controlling for all other confounding factors. Using state-level data from Mexico, we find a significant effect of climate-driven changes in crop yields on the rate of emigration to the United States. The estimated semielasticity of emigration with respect to crop yields is approximately −0.2, i.e., a 10% reduction in crop yields would lead an additional 2% of the population to emigrate. We then use the estimated semielasticity to explore the potential magnitude of future emigration. Depending on the warming scenarios used and adaptation levels assumed, with other factors held constant, by approximately the year 2080, climate change is estimated to induce 1.4 to 6.7 million adult Mexicans (or 2% to 10% of the current population aged 15-65 y) to emigrate as a result of declines in agricultural productivity alone. Although the results cannot be mechanically extrapolated to other areas and time periods, our findings are significant from a global perspective given that many regions, especially developing countries, are expected to experience significant declines in agricultural yields as a result of projected warming.human migration | global warming | environmental migrants | agricultural productivity | instrumental variables approach

Standard-Nutzungsbedingungen:Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden.Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen.Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. www.econstor.eu We analyze a unique and extensive set of panel data characterizing annual bilateral international migration flows from 163 origin countries to 42 OECD destination countries covering the last three decades. We find a positive and statistically significant relationship between temperature and international outmigration only in the most agriculture-dependent countries, consistent with the widely-documented adverse impact of temperature on agricultural productivity. In addition, migration flows to current major destinations are especially temperature-sensitive. Policies to address issues related to climate-induced international migration would be more effective if focused on the agriculturedependent countries and especially people in those countries whose livelihoods depend on agriculture. Terms of use: Documents in D I S C U S S I O N P A P E R S E R I E SJEL Classification: Q54, J10

Any opinions and conclusions expressed herein are those of the authors and do not necessarily represent the views of the U.S. Census Bureau. All results have been reviewed to ensure that no confidential information is disclosed. the referees, for their helpful comments and suggestions on earlier versions of this paper. Abstract Although most research on US income inequality trends is based on public-use March CPS data, a new wave of research using IRS tax return data reports substantially higher levels of inequality and faster growing trends for recent years. We show that these apparently inconsistent estimates are largely reconciled when the income distribution and inequality are defined in the same way. Using internal CPS data for 1967-2006, we show that estimates of top income shares based on internal CPS data for 1967-2006 are similar in many respects to the IRS data-based estimates reported by Piketty and Saez (2003). Our results imply that changes in US income inequality since 1993 are largely driven by changes in the share of the top 1 percent.

Standard-Nutzungsbedingungen:Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden.Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen.Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. www.econstor.eu The Institute for the Study of Labor (IZA) in Bonn is a local and virtual international research center and a place of communication between science, politics and business. IZA is an independent nonprofit organization supported by Deutsche Post Foundation. The center is associated with the University of Bonn and offers a stimulating research environment through its international network, workshops and conferences, data service, project support, research visits and doctoral program. IZA engages in (i) original and internationally competitive research in all fields of labor economics, (ii) development of policy concepts, and (iii) dissemination of research results and concepts to the interested public. Terms of use: Documents in D I S C U S S I O N P A P E R S E R I E SIZA Discussion Papers often represent preliminary work and are circulated to encourage discussion. Citation of such a paper should account for its provisional character. A revised version may be available directly from the author.IZA Discussion Paper No. 6853 September 2012 ABSTRACT Access to Public Schools and the Education of Migrant Children in China *A significant proportion of migrant children in China are not able to attend public schools for lack of local household registration (HuKou), and turn to privately-operated migrant schools. This paper examines the consequences of such a partially involuntary school choice, using survey data and standardized test scores from field work conducted in Shanghai. We find that migrant students who are unable to enroll in public schools perform significantly worse than their more fortunate counterparts in both Chinese and Mathematics. We also use parental satisfaction and parental assessment of school quality as alternative measures of the educational outcome and find similar results. Our study suggests that access to public schools is the key factor determining the quality of education that migrant children receive.JEL Classification: I28, J15, O15

We analyze trends in US size-adjusted household income inequality between 1975 and 2004 using the most commonly used data source -the public use version of the March Current Population Survey. But, unlike most researchers, we also give substantial attention to the problems caused by the topcoding of each income source in the CPS data. Exploiting our access to Census Bureau internal CPS data, we examine estimates from data incorporating imputations for topcoded incomes derived from cell means and estimates from data multiplyimputed from parametric distribution models. Our analysis yields robust conclusions about inequality trends. The upward trend in US income inequality that began in the mid-1970s and increased in the 1980s slowed markedly after 1993.

Using the internal March CPS, we create and in this paper distribute to the larger research community a cell mean series that provides the mean of all income values above the topcode for any income source of any individual in the public use March CPS that has been topcoded since 1976. We also describe our construction of this series. When we use this series together with the public use March CPS, we closely match the yearly mean income levels and income inequalities of the U.S. population found using the internal March CPS data.

The unemployment rate is among the most important and carefully-watched economic indicators in modern society, and often takes center stage in discussions of economic policy. However, there is considerable disagreement over the precise definition and measurement of unemployment, hence the other two labor force statuses: "employed" and "not-in-labor-force." 1 In the United States, the Bureau of Labor Statistics (BLS) reports six alternative measures of unemployment (U1-U6), including the official unemployment rate (U3) which is based on the International Labor Organization (ILO)'s definition. 2 Due to the intrinsic difficulties in classifying some groups of people, such as marginally-attached workers and involuntary part-time workers, into the three distinct labor force statuses, the US official unemployment rate is potentially subject to measurement error.In this paper, we take a latent variables approach and view the reported labor force statuses as functions of the underlying unobserved true labor force statuses. We then impose a structure on the misclassification process and the dynamics of the underlying latent labor force statuses. Using recent results in the measurement error literature, we show that the official US unemployment rate substantially underestimates the true level of unemployment. During the period from January 1996 to August 2011, our corrected unemployment rates are higher than the corresponding official figures by 2.1 percentage points on average. In terms of the monthly differences, the corrected rates are from 1 to 4.4 percentage points higher than the official rates, and are more sensitive to changes in the business cycles.Official unemployment statistics in the United States are based on the Current Population Survey (CPS) conducted by the Census Bureau. The CPS interviews around 60,000 households each month to collect basic demographic and labor force status information. Based on the answers to survey questions on job-related activities, the CPS records each individual's labor force status as "employed," "unemployed," or "not-in-labor-force." The misclassification among the three possible values of the 1 For example, using Canadian data, Jones and Riddell (1999) empirically examine labor market transitions of people with different labor force statuses and find substantial heterogeneity within the nonemployed, such that no dichotomy exists between those unemployed and not-in-labor-force among all nonemployed persons.2 The ILO defines "unemployed" as those who are currently not working but are willing and able to work for pay, currently available to work, and have actively searched for work.

Although most research on US income inequality trends is based on public-use March CPS data, a new wave of research using IRS tax return data reports substantially higher levels of inequality and faster growing trends for recent years. We show that these apparently inconsistent estimates are largely reconciled when the income distribution and inequality are defined in the same way.