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Experimental Benchmarking
Experimental benchmarking allows researchers to learn about the accuracy of non-experimental research designs. Specifically, one can compare observational results to experimental findings to calibrate bias. Under ordinary conditions, carrying out an experiment gives the researchers an unbiased estimate of their parameter of interest. This estimate can then be compared to the findings of observational research. Note that benchmarking is an attempt to calibrate non-statistical uncertainty (flaws in underlying assumptions). When combined with meta-analysis this method can be used to understand the scope of bias associated with a specific area of research. History The start of experimental benchmarking in social science is often attributed to Robert LaLonde. In 1986 he found that findings of econometric procedures assessing the effect of an employment program on trainee earnings did not recover the experimental findings. Experimental benchmarking is often conducted in medical r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uncertainty
Uncertainty or incertitude refers to situations involving imperfect or unknown information. It applies to predictions of future events, to physical measurements that are already made, or to the unknown, and is particularly relevant for decision-making. Uncertainty arises in partially observable or stochastic environments, as well as due to ignorance, Laziness, indolence, or both. It arises in any number of fields, including insurance, philosophy, physics, statistics, economics, finance, medicine, psychology, sociology, engineering, metrology, meteorology, ecology and information science. Concepts Although the terms are used in various ways among the general public, many specialists in decision theory, statistics and other quantitative fields have defined uncertainty, risk, and their measurement as: Uncertainty The lack of certainty, a state of limited knowledge where it is impossible to exactly describe the existing state, a future outcome, or more than one possible outcome. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert LaLonde
Robert John LaLonde (1958–2018) was an American economist who specialized in the fields of labor economics and econometrics. He grew up in Syracuse, NY and attended Westhill High School. He received his A.B. degree from the University of Chicago in 1980. He then attended Princeton University, where he received his Ph.D. in 1985 under the supervision of Orley Ashenfelter. His own Ph.D. students included Brian Jacob. He joined the faculty of the University of Chicago in 1985 as Associate Professor of Industrial Relations at the Graduate School of Business and was a Visiting Associate Professor of The Harris Graduate School of Public Policy Studies from 1994-1995. In 1995, LaLonde joined Michigan State University as an Associate Professor of Economics for three years. In 1999, he went on to spend the remainder of his professional career at the University of Chicago, where he was professor and director of the Ph.D. program in the Harris School of Public Policy. In addition to his a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propensity Score Matching
In the statistical analysis of observational data, propensity score matching (PSM) is a statistical matching technique that attempts to estimate the effect of a treatment, policy, or other intervention by accounting for the covariates that predict receiving the treatment. PSM attempts to reduce the bias due to confounding variables that could be found in an estimate of the treatment effect obtained from simply comparing outcomes among units that received the treatment versus those that did not. Paul R. Rosenbaum and Donald Rubin introduced the technique in 1983, defining the propensity score as the conditional probability of a unit (e.g., person, classroom, school) being assigned to the treatment, given a set of observed covariates. The possibility of bias arises because a difference in the treatment outcome (such as the average treatment effect) between treated and untreated groups may be caused by a factor that predicts treatment rather than the treatment itself. In ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverse Probability Weighting
Inverse probability weighting is a statistical technique for estimating quantities related to a population other than the one from which the data was collected. Study designs with a disparate sampling population and population of target inference (target population) are common in application. There may be prohibitive factors barring researchers from directly sampling from the target population such as cost, time, or ethical concerns. A solution to this problem is to use an alternate design strategy, e.g. stratified sampling. Weighting, when correctly applied, can potentially improve the efficiency and reduce the bias of unweighted estimators. One very early weighted estimator is the Horvitz–Thompson estimator of the mean. When the sampling probability is known, from which the sampling population is drawn from the target population, then the inverse of this probability is used to weight the observations. This approach has been generalized to many aspects of statistics under vario ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facebook
Facebook is a social media and social networking service owned by the American technology conglomerate Meta Platforms, Meta. Created in 2004 by Mark Zuckerberg with four other Harvard College students and roommates, Eduardo Saverin, Andrew McCollum, Dustin Moskovitz, and Chris Hughes, its name derives from the face book directories often given to American university students. Membership was initially limited to Harvard students, gradually expanding to other North American universities. Since 2006, Facebook allows everyone to register from 13 years old, except in the case of a handful of nations, where the age requirement is 14 years. , Facebook claimed almost 3.07 billion monthly active users worldwide. , Facebook ranked as the List of most-visited websites, third-most-visited website in the world, with 23% of its traffic coming from the United States. It was the most downloaded mobile app of the 2010s. Facebook can be accessed from devices with Internet connectivit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petra Todd
Petra Elisabeth (Crockett) Todd is an American economist whose research interests include labor economics, development economics, microeconomics, and econometrics. She is the Edward J. and Louise W. Kahn Term Professor of Economics at the University of Pennsylvania, and is also affiliated with the University of Pennsylvania Population Studies Center, the Human Capital and Equal Opportunity Global Working Group (HCEO), the IZA Institute of Labor Economics and the National Bureau of Economic Research. Education and career Petra Todd graduated from the University of Virginia in 1989 with a double major in economics and English. She did her graduate studies in economics at the University of Chicago, completing her Ph.D. in 1996. Her dissertation, ''Three Essays on Empirical Methods for Evaluating the Impact of Policy Interventions in Education and Training'', was jointly supervised by James Heckman, Hidehiko Ichimura, and Derek Allen Neal. She has been a faculty member at the Univ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
