Margaret Slade (economist)

Margaret Slade
They use an econometric regression with instrumental variables to measure cross price elasticity coefficients. They prove that the estimators are consistent and asymptotically distributed. This approach allowed them to compare models of global competition, where all firms compete with one another, and local competition, where firms only compete with their respective neighbours. The data used for this study was obtained for U.S. wholesale gasoline markets which mostly have localized competition. Slade used data for metals listed on commodity exchanges by price-setting producers to examine how different organizations of markets are linked to behaviour of prices.

Proxy (statistics)

proxyproxiesproxy variable
. * Instrumental variable. Latent variable. Operationalization. Proxy (climate).

Racial segregation

Racial segregation is the systemic separation of people into racial or other ethnic groups in daily life. Segregation can involve spatial separation of the races, and mandatory use of different institutions, such as schools and hospitals by people of different races. Specifically, it may apply to activities such as eating in a restaurant, drinking from a water fountain, using a public toilet, attending school, going to the movies, riding on a bus, or in the rental or purchase of a home or of hotel rooms. In addition, segregation often allowed close contact in hierarchical situations, such as allowing a person of one race to work as a servant for a member of another race.

Outline of regression analysis

Instrumental variables regression. Quantile regression. Generalized additive model. Autoregressive model. Moving average model. Autoregressive moving average model. Autoregressive integrated moving average. Autoregressive conditional heteroskedasticity. Prediction. Design of experiments. Data transformation. Box–Cox transformation. Machine learning. Analysis of variance. Causal inference.

Stephen Machin

Stephen Jonathan Machin (born 23 December 1962 ) is a British economist and professor of economics at the London School of Economics (LSE). Moreover, he is currently director of the Centre for Economic Performance (CEP) and is a fellow of the British Academy and Society of Labor Economists. His current research interests include labour market inequality, the economics of education, and the economics of crime.

Heckman correction

Heckit modelHeckman selection correctionHeckman selection model
The Heckman correction is a statistical technique to correct bias from non-randomly selected samples or otherwise incidentally truncated dependent variables, a pervasive issue in quantitative social sciences when using observational data. Conceptually, this is achieved by explicitly modelling the individual sampling probability of each observation (the so-called selection equation) together with the conditional expectation of the dependent variable (the so-called outcome equation). The resulting likelihood function is mathematically similar to the Tobit model for censored dependent variables, a connection first drawn by James Heckman in 1976.


IV (disambiguation)
Instrumental variable, in statistics. Intrinsic value (finance), of an option or stock. Intrinsic viscosity. Trochlear nerve, the fourth cranial nerve. 4 (number) in Roman numerals. International Viewpoint, an online magazine of the Trotskyist reunified Fourth International. Inter vivos trust, a legal instrument.

Causal model

Causal diagramcausal model theorycausal modeling
An instrumental variable is one that: Regression coefficients can serve as estimates of the causal effect of an instrumental variable on an outcome as long as that effect is not confounded. In this way, instrumental variables allow causal factors to be quantified without data on confounders. For example, given the model: Z is an instrumental variable, because it has a path to the outcome Y and is unconfounded, e.g., by U. In the above example, if Z and X take binary values, then the assumption that Z = 0, X = 1 does not occur is called monotonicity.

Observational study

observational studiesobservationalobservational data
Instrumental variable. Scientific method. Theory ladenness. Quantitative research. "NIST/SEMATECH Handbook on Engineering Statistics" at NIST.

Regression discontinuity design

regression discontinuity
The intuition behind it is related to the instrumental variable strategy and intention to treat. When the assignment variable is continuous (e.g. student aid) and depends predictably on another observed variable (e.g. family income), one can identify treatment effects using sharp changes in the slope of the treatment function. This technique was coined regression kink design by Nielsen, Sørensen, and Tabe (2010), though they cite similar earlier analyses. They write, "This approach resembles the regression discontinuity idea. Instead of a discontinuity of in the level of the stipend-income function, we have a discontinuity in the slope of the function."

Correlation does not imply causation

Cum hoc ergo propter hoccausationcorrelation
False inferences of causation due to reverse causation (or wrong estimates of the magnitude of causation due the presence of bidirectional causation) can be avoided by using explanators (regressors) that are necessarily exogenous, such as physical explanators like rainfall amount (as a determinant of, say, futures prices), lagged variables whose values were determined before the dependent variable's value was determined, instrumental variables for the explanators (chosen based on their known exogeneity), etc. See Causality#Statistics and economics.

Preston curve

In economic research, this kind of problem has traditionally been dealt with through the use of instrumental variables which allow the researcher to separate out one effect from another. This strategy requires identification of an "instrument" – i.e. a variable which correlates with per capita income but not with the error term in the linear regression. However, since any variable which is likely to correlate with income is also likely to correlate strongly with health and life expectancy this is a difficult task.

Predetermined variables

Predetermined variables are variables that were determined prior to the current period. In econometric models this implies that the current period error term is uncorrelated with current and lagged values of the predetermined variable but may be correlated with future values. This is a weaker restriction than strict exogeneity, which requires the variable to be uncorrelated with past, present, and future shocks.

Hadamard derivative

Hadamard derivative is a concept of directional derivative for maps between Banach spaces. It is particularly suited for applications in stochastic programming and asymptotic statistics.