Effective sample size

Topic of Markov chains, Gibbs sampling, and Metropolis–Hastings, part of Bayesian statistics

Effective sample size

Type Topic
Taught in Markov chains, Gibbs sampling, and Metropolis–Hastings
Part Bayesian statistics
Questions using it 1

The number of independent draws that would give the same Monte Carlo precision as M correlated MCMC draws, roughly M/(1+2\sum_{k\ge1}\rho_k) for lag-k autocorrelations \rho_k. Strong autocorrelation makes it much smaller than M.

In Markov chains, Gibbs sampling, and Metropolis–Hastings

where B is the number of discarded iterations. Because the draws are dependent, L correlated draws contain less information than L independent draws. Autocorrelation, trace plots, multiple chains, and effective sample size are therefore part of a serious analysis.

Used in

See also

Monte Carlo method · Precision · Markov chain · Autocorrelation function · Warm-up is not a convergence proof · Stationarity and detailed balance · Detailed balance implies stationarity · Systematic-scan Gibbs sampler

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