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Instrumental Variable
In statistics, econometrics, epidemiology and related disciplines, the method of instrumental variables (IV) is used to estimate causal relationships when controlled experiments are not feasible or when a treatment is not successfully delivered to every unit in a randomized experiment. Intuitively, IVs are used when an explanatory variable of interest is correlated with the error term (endogenous), in which case ordinary least squares and ANOVA give biased results. A valid instrument induces changes in the explanatory variable (is correlated with the endogenous variable) but has no independent effect on the dependent variable and is not correlated with the error term, allowing a researcher to uncover the causal effect of the explanatory variable on the dependent variable. Instrumental variable methods allow for consistent estimation when the explanatory variables (covariates) are correlated with the error terms in a regression model. Such correlation may occur when: # changes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statistics
Statistics (from German language, German: ', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data. In applying statistics to a scientific, industrial, or social problem, it is conventional to begin with a statistical population or a statistical model to be studied. Populations can be diverse groups of people or objects such as "all people living in a country" or "every atom composing a crystal". Statistics deals with every aspect of data, including the planning of data collection in terms of the design of statistical survey, surveys and experimental design, experiments. When census data (comprising every member of the target population) cannot be collected, statisticians collect data by developing specific experiment designs and survey sample (statistics), samples. Representative sampling assures that inferences and conclusions can reasonably extend from the sample ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endogeneity (econometrics)
In econometrics, endogeneity broadly refers to situations in which an explanatory variable is correlated with the error term. The distinction between endogenous and exogenous variables originated in simultaneous equations models, where one separates variables whose values are determined by the model from variables which are predetermined. Ignoring simultaneity in the estimation leads to biased estimates as it violates the exogeneity assumption of the Gauss–Markov theorem. The problem of endogeneity is often ignored by researchers conducting non-experimental research and doing so precludes making policy recommendations. Instrumental variable techniques are commonly used to mitigate this problem. Besides simultaneity, correlation between explanatory variables and the error term can arise when an unobserved or omitted variable is confounding both independent and dependent variables, or when independent variables are measured with error. Exogeneity versus endogeneity In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Regression
In statistics, linear regression is a statistical model, model that estimates the relationship between a Scalar (mathematics), scalar response (dependent variable) and one or more explanatory variables (regressor or independent variable). A model with exactly one explanatory variable is a ''simple linear regression''; a model with two or more explanatory variables is a multiple linear regression. This term is distinct from multivariate linear regression, which predicts multiple correlated dependent variables rather than a single dependent variable. In linear regression, the relationships are modeled using linear predictor functions whose unknown model parameters are estimation theory, estimated from the data. Most commonly, the conditional mean of the response given the values of the explanatory variables (or predictors) is assumed to be an affine function of those values; less commonly, the conditional median or some other quantile is used. Like all forms of regression analysis, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Statistical Review
The International Statistical Institute (ISI) is a professional association of statisticians. At a meeting of the Jubilee Meeting of the Royal Statistical Society, statisticians met and formed the agreed statues of the International Statistical Institute. It was founded in 1885, although there had been international statistical congresses since 1853. The institute has about 4,000 members from government, academia, and the private sector. The affiliated associations have membership open to any professional statistician. The institute publishes a variety of books and journals, and holds an international conference every two years. The biennial convention was commonly known as the ISI Session; however, since 2011, it is now referred to as the ISI World Statistics Congress. The permanent office of the institute is located in thStatistics Netherlands (CBS)building in the Leidschenveen-Ypenburg district of The Hague, in the Netherlands. It was established in 1913 to preserve documen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Heckman
James Joseph Heckman (born April 19, 1944) is an American economist and Nobel laureate who serves as the Henry Schultz Distinguished Service Professor in Economics at the University of Chicago, where he is also a professor at the college, a professor at the Harris School of Public Policy, Director of the Center for the Economics of Human Development (CEHD), and co-director of Human Capital and Economic Opportunity (HCEO) Global Working Group. He is also a professor of law at the Law School, a senior research fellow at the American Bar Foundation, and a research associate at the NBER. He received the John Bates Clark Medal in 1983, and the Nobel Memorial Prize in Economic Sciences in 2000, which he shared with Daniel McFadden. He is known principally for his pioneering work in econometrics and microeconomics. Heckman is noted for his contributions to selection bias and self-selection in quantitative analysis in the social sciences, especially the Heckman correction, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alan Krueger
Alan Bennett Krueger (September 17, 1960 – March 16, 2019) was an American economist who was the James Madison Professor of Political Economy at Princeton University and Research Associate at the National Bureau of Economic Research. He served as Assistant Secretary of the Treasury for Economic Policy, nominated by President Barack Obama, from May 2009 to October 2010, when he returned to Princeton. He was nominated in 2011 by Obama as chair of the White House Council of Economic Advisers, and served in that office from November 2011 to August 2013. He was among the 50 highest ranked economists in the world according to Research Papers in Economics. He made innovative use of natural experiments in economics, including influential research in the 1990s that challenged the dominant perspective in economics at the time that minimum wage adversely affected employment. He also made prominent contributions to research on inequality and the economic effects of education. Early life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joshua Angrist
Joshua David Angrist (; born September 18, 1960) is an Israeli American economist and Ford Professor of Economics at the Massachusetts Institute of Technology. Angrist, together with Guido Imbens, was awarded the Nobel Memorial Prize in Economics in 2021 "for their methodological contributions to the analysis of causal relationships". He ranks among the world's top economists in labor economics, urban economics, econometrics, and the economics of education, and is known for his use of quasi-experimental research designs (such as instrumental variables) to study the effects of public policies and changes in economic or social circumstances. He is a co-founder and co-director of MIT's Blueprint Labs, which researches the relationship between human capital and income inequality in the U.S. He also cofounded Avela, an ed-tech startup that provides application and enrollment-related software and services to school districts, schools of all kinds, organizations like Teach f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Judea Pearl
Judea Pearl (; born September 4, 1936) is an Israeli-American computer scientist and philosopher, best known for championing the probabilistic approach to artificial intelligence and the development of Bayesian networks (see the article on belief propagation). He is also credited for developing a theory of causal and counterfactual inference based on structural models (see article on causality). In 2011, the Association for Computing Machinery (ACM) awarded Pearl with the Turing Award, the highest distinction in computer science, "for fundamental contributions to artificial intelligence through the development of a calculus for probabilistic and causal reasoning". He is the author of several books, including the technical '' Causality: Models, Reasoning and Inference'', and '' The Book of Why'', a book on causality aimed at the general public. Judea Pearl is the father of journalist Daniel Pearl, who was kidnapped and murdered by terrorists in Pakistan connected with Al-Qaeda a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panel Data
In statistics and econometrics, panel data and longitudinal data are both multi-dimensional data involving measurements over time. Panel data is a subset of longitudinal data where observations are for the same subjects each time. Time series and cross-sectional data can be thought of as special cases of panel data that are in one dimension only (one panel member or individual for the former, one time point for the latter). A literature search often involves time series, cross-sectional, or panel data. A study that uses panel data is called a longitudinal study or panel study. Example In the multiple response permutation procedure (MRPP) example above, two datasets with a panel structure are shown and the objective is to test whether there's a significant difference between people in the sample data. Individual characteristics (income, age, sex) are collected for different persons and different years. In the first dataset, two persons (1, 2) are observed every year for three ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Errors-in-variables Models
In statistics, an errors-in-variables model or a measurement error model is a regression model that accounts for measurement errors in the independent variables. In contrast, standard regression models assume that those regressors have been measured exactly, or observed without error; as such, those models account only for errors in the dependent variables, or responses. In the case when some regressors have been measured with errors, estimation based on the standard assumption leads to inconsistent estimates, meaning that the parameter estimates do not tend to the true values even in very large samples. For simple linear regression the effect is an underestimate of the coefficient, known as the '' attenuation bias''. In non-linear models the direction of the bias is likely to be more complicated. Motivating example Consider a simple linear regression model of the form : y_ = \alpha + \beta x_^ + \varepsilon_t\,, \quad t=1,\ldots,T, where x_^ denotes the ''true'' but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olav Reiersøl
Olav Reiersøl (28 June 1908 – 14 February 2001) was a Norwegian statistician and econometrician, who made several substantial contributions to econometrics and statistics. His works on identifiability and instrumental variables are standard references both in econometrics and statistics, and his work on genetic algebras are frequently cited in genetics. Reiersøl became interested in the international language Esperanto at a young age, and later in life used it to keep in touch with other mathematicians. He was one of the founders of the Esperanto association ''Internacia Asocio de Esperantistaj Matematikistoj'' ("International Association of Esperantist Mathematicians"). ''Econometric Theory'', 16, 2000, 113-125. He was made a fellow of the |
Journal Of Economic Perspectives
The ''Journal of Economic Perspectives'' (''JEP'') is an economic journal published by the American Economic Association. The journal was established in 1987. The JEP was founded by Joseph Stiglitz, Carl Shapiro, and Timothy Taylor. It is oriented around the twin goals of "providing perspective on current economic research, and explaining how economics provides perspective on questions of general interest." According to its editors its purpose is: #to synthesize and integrate lessons learned from active lines of economic research; #to provide economic analysis of public policy issues; to encourage cross-fertilization of ideas among the fields of thinking; #to offer readers an accessible source for state-of-the-art economic thinking; #to suggest directions for future research; #to provide insights and readings for classroom use; #and to address issues relating to the economics profession. Its current editors are Heidi Williams and Jeffrey Kling, and its managing editor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
