Statistics — Page 23
Explore statistical methods, their assumptions, interpretation and limitations.
Research field
Method family
Kolmogorov-Smirnov Test
The Kolmogorov-Smirnov (KS) test is a nonparametric goodness-of-fit test that assesses whether a sample comes from a specified theoretical distribution, such as the normal or exponential. First formalised by Andrey Kolmogorov in 1933 and fu...
Kriging
Kriging is a geostatistical method that predicts the value of a continuous variable at unmeasured locations from nearby measurements, using the spatial correlation structure captured by a variogram. Formalised by Georges Matheron in 1963, i...
Kruskal-Wallis test
The Kruskal-Wallis H test is a nonparametric hypothesis test that compares three or more independent groups to decide whether their distributions (typically their medians) differ. Introduced by William Kruskal and W. Allen Wallis in 1952, i...
Kónya Bootstrap Causality
Introduced by László Kónya in 2006, this method tests Granger causality in heterogeneous panels by estimating a Seemingly Unrelated Regressions (SUR) system and deriving country-specific critical values through bootstrapping. Unlike pooled...
LCA
Latent class analysis is a probabilistic model-based clustering technique that identifies unobserved subgroups — latent classes — within a population on the basis of patterns of categorical, binary, or ordinal indicator responses. Originati...
LGC Model
The latent growth curve model is a structural equation modelling approach introduced by Meredith and Tisak (1990) for analysing change over time. It treats each individual's starting point (intercept) and rate of change (slope) as latent va...
LISA
LISA, introduced by Luc Anselin in 1995, is a local statistic that computes spatial autocorrelation separately for every observation rather than for the map as a whole. It pinpoints where high or low values cluster and where spatial outlier...
LSDVC
LSDVC is a bias-corrected panel data estimator introduced by Kiviet (1995) to address the well-known Nickell bias that afflicts the standard Least Squares Dummy Variable (LSDV) estimator in dynamic panel models with a lagged dependent varia...
Landmark Analysis
Landmark analysis, introduced by Anderson, Cain, and Gelber in 1983, estimates conditional survival probabilities for subjects who are still at risk at a pre-specified point in time — the landmark — rather than at study entry. It was develo...
Laplace Approximation
The Laplace approximation is a classical analytic technique that replaces an intractable posterior distribution with a multivariate Gaussian centred at the posterior mode, using the curvature of the log-posterior at that mode to set the cov...
Latent Class Analysis
Latent class analysis identifies unobserved subgroups — latent classes — within a population by finding patterns of responses across a set of categorical observed indicators. It is the categorical-variable counterpart of cluster analysis, b...
Latent Profile Analysis
Latent Profile Analysis (LPA) is a person-centered finite mixture modeling technique that identifies unobserved subgroups — called profiles — within a population based on patterns of scores across multiple continuous indicators. Rooted in L...
Latent Transition Analysis
Latent Transition Analysis (LTA) is a method for studying transitions between latent classes over time, developed by Collins and Lanza (2010). LTA combines latent class analysis (grouping individuals into classes) with Markovian transition...
Latent Transition Analysis in Education
Latent transition analysis (LTA) is a longitudinal extension of latent class analysis that models how individuals move between qualitatively distinct, unobserved categories over time. In education it represents students as belonging to lear...
Latent-Class Choice Segmentation
Latent-class choice segmentation estimates consumer market segments and their preferences at the same time, by fitting a finite mixture of discrete-choice models to individual purchase or choice data. Wagner Kamakura and Gary Russell introd...
Least Median of Squares
Least Median of Squares is a robust linear regression method introduced by Peter J. Rousseeuw in 1984. Instead of minimising the sum of squared residuals like ordinary least squares, it minimises the median of the squared residuals, which l...
Least Trimmed Squares
Least Trimmed Squares is a robust linear regression method introduced by Peter J. Rousseeuw in 1984. Instead of fitting all residuals, it estimates the coefficients by minimising the sum of only the h smallest squared residuals, which gives...
Lee-Carter Model
The Lee-Carter model is a stochastic framework for modeling and forecasting age-specific mortality rates, introduced by Ronald Lee and Lawrence Carter in their landmark 1992 paper. It decomposes the logarithm of age-specific death rates int...
Lee-Carter Mortality Model
The Lee-Carter model is the benchmark method for forecasting human mortality. Introduced by Ronald Lee and Lawrence Carter in 1992 for U.S. data, it captures the entire schedule of age-specific death rates with a remarkably parsimonious str...
Lee-Strazicich Test
The Lee-Strazicich (2003) test is a Lagrange Multiplier-based unit-root test that allows for two endogenous structural breaks under both the null and alternative hypotheses. Proposed by Junsoo Lee and Mark C. Strazicich, it corrects a funda...
Levene and Brown-Forsythe Test
The Levene and Brown-Forsythe test checks whether two or more groups share the same variance (homogeneity of variance). Levene (1960) built the test on absolute deviations from each group mean, and Brown and Forsythe (1974) made it robust t...
Levin-Lin-Chu Test
The Levin-Lin-Chu (LLC) test, introduced by Levin, Lin, and Chu (2002), is a first-generation panel unit-root test that pools cross-sectional information to test whether all units in a panel share a common autoregressive unit root. It is wi...
Libor Market Model
The LIBOR Market Model (BGM), developed by Brace, Gatarek, and Musiela (1997), is a multi-factor interest rate model that directly models forward LIBOR rates as lognormal processes. Unlike short-rate models, LMM naturally prices caplets at...
Life Table
A life table is a systematic, age-structured summary of the mortality experience of a population. It traces a hypothetical cohort of births — conventionally 100,000 — through successive age intervals, recording how many survive, how many di...