NEWS
NMAR 0.1.2 (2026-02-05)
- Bootstrap replicate evaluation backend is now configurable via
options(nmar.bootstrap_apply = "auto"|"base"|"future"). Default bootstrap behavior (nmar.bootstrap_apply = "auto") uses base::lapply() unless the current future plan has more than one worker; if so, it uses future.apply::future_lapply(future.seed = TRUE) when available.
- Exptilt validation now rejects non-finite values (e.g.,
Inf, -Inf) in covariates (and non-finite observed outcomes).
NMAR 0.1.1 (2026-01-16)
- CRAN release-related fixes
- Fix
return roxygen keyword in S3 Functions
- Add research doi references to DESCRIPTION file
NMAR 0.1.0
Initial CRAN Release
- First release of the NMAR package for estimating nonignorable nonresponse (NMAR) bias in survey data.
Methods
- Empirical Likelihood (EL): Added
el_engine() implementing the estimator of Qin, Leung, and Shao (2002). This method uses empirical likelihood weights satisfying response mechanism equations and auxiliary moment constraints.
- Exponential Tilting (Parametric & Nonparametric): Included robust implementations for both microdata (
exptilt_engine) and aggregated contingency tables (exptilt_nonparam_engine) based on Riddles, Kim, and Im (2016).
Key Features
- Unified API: All estimators are accessible via a single, consistent
nmar() interface supporting standard formula syntax (e.g., Y ~ X | Z).
- Complex Survey Support: Seamless integration with the
survey package. nmar() accepts survey.design objects, automatically handling weights and stratification.
- Variance Estimation: Robust bootstrapping (S3) implementation for standard errors and confidence intervals across all engines.
- Diagnostics: Rich return objects including convergence statistics, Jacobian condition numbers, and detailed weight summaries.
Major Changes
- Refactored Architecture: The
exptilt and el engines share a unified structural design, ensuring consistent behavior for controls, standardization, and error handling.
- Standardization: Added
standardize = TRUE argument to engines to improve numerical stability during optimization.