:</p><ul>
<li><p><code>tauestimate</code>: A vector of estimates for pairwise treatment
    effects</p></li>
<li><p><code>varestimate</code>: A vector of variance estimates for
    <code>tauestimate</code>, using Abadie &amp; Imbens (2006)'s method</p></li>
<li><p><code>varestimateAI2012</code>: A vector of variance estimates for
    <code>tauestimate</code>, when matching on the generalized propensity score,
    using Abadie &amp; Imbens (2016)'s method. This variance estimate takes into account
    of the