I. STEPWISE REGRESSION METHODS
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Backward elimination (AIC)
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Moderate
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Do not incorporate model uncertainty in the estimation of regression coefficients and standard errors.
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Model selection: 5.4 s
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Estimation of SE with bootstrapb: 30.9 s
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Backward elimination (BIC)
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Very poor
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Model selection: 5.6 s
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Estimation of SE with bootstrapb: 15.0 s
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Backward elimination (LRT)
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Moderate
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Model selection: 5.1 s
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Estimation of SE with bootstrapb: 19.2 s
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Forward selection (AIC)
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Moderate
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Model selection: 2.8 s
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Estimation of SE with bootstrapb: 28.5 s
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Forward selection (BIC)
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Very poor
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Model selection: 1.9 s
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Estimation of SE with bootstrapb: 13.8 s
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Forward selection (LRT)
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Moderate
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Model selection: 3.1 s
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Estimation of SE with bootstrapb: 19.8 s
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II. PENALIZED REGRESSION METHODS
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Lasso
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Poor (λmin)
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Model uncertainty is partially incorporated into the estimation and inference procedure via λ tuning step, and estimation of standard errors using bootstrap.
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Lasso algorithm: 0.02 s
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Good (λ1se)
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10-fold CV: 0.5 s
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Estimation of SE with bootstrapb: 394.0 s
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Adaptive lasso
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Good (λmin)
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Estimation of weights (ridge regression): 1.6 s
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Good (λ1se)
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Adaptive lasso algorithm: 0.02 s
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10-fold CV: 0.5 s
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Estimation of SE with bootstrapb: 411.2 s
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Adaptive elastic net
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Good (λmin)
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Estimation of weights (ridge regression): 1.6 s
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Good (λ1se)
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Estimation of λ for L2 penalty (elastic net): 1.2 s
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Adaptive elastic net algorithm: 0.2 s
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10-fold CV: 1.4 s
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Estimation of SE with bootstrapb: 3,265.3 s
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III. BAYESIAN MODEL AVERAGING
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Bayesian model averaging (using MCMC to search model space)
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PIPs of regression covariates inform model selection. Bootstrap gave selection frequencies that were almost identical to PIPs (data not shown).
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Model uncertainty is properly incorporated into the estimation of regression coefficients and their standard deviations (provided that MCMC chain converged and the algorithms managed to search the entire model space).
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250.8 s
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(1,000,000 iterations, chain converged)
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