Imai, Kosuke, Ying Lu, and Aaron Strauss (2011). ``eco: R Package for Ecological Inference in 2 x 2 Tables'' Journal of Statistical Software. Vol. 42, No. 5 (Special Volume on Political Methodology), pp. 1-23.



eco is a publicly available R package that implements the Bayesian and likelihood methods proposed in Imai, Lu, and Strauss (2008) for ecological inference in 2 x 2 tables as well as the method of bounds introduced by Duncan and Davis (1953). The package fits both parametric and nonparametric models using either the Expectation-Maximization algorithms (for likelihood models) or the Markov chain Monte Carlo algorithms (for Bayesian models). For all models, the individual-level data can be directly incorporated into the estimation whenever such data are available. Along with in-sample and out-of-sample predictions, the package also provides a functionality which allows one to quantify the effect of data aggregation on parameter estimation and hypothesis testing under the parametric likelihood models.

  Current Version

The current version is 3.1-7 (built on 03/19/15) which runs on R 2.0.0 and higher. The source code is available for download from The Comprehensive R Archive Network (CRAN)


Regardless of one's operating system, the software can be installed by typing the following command at R prompt:

> install.packages("eco")

This will install the latest version from CRAN.


The complete documentation is available in pdf format. The software also comes with standard R help files.

© Kosuke Imai
Last modified: Tue Feb 10 08:50:46 EST 2015