 uncertainty in estimating the GPS. This variable is named AI2012
    (not AI2016) for backwards compatibility.</p></li>
<li><p><code>analysis_idx</code>: a list containing the indices_kept (analyzed)
    and indices_dropped (trimmed) based on Crump et al. (2009)'s method.</p></li>
</ul>

    
    <h2 class="hasAnchor" id="references"><a class="anchor" href="#references"></a>References</h2>

    <p>Yang, S., Imbens G. W., Cui, Z., Faries, D. E., &amp; Kadziola, Z.
  (2016) Propensity Score Matching and Subc