x-tex">\tau = 0.297</annotation></semantics></math>.</p>
<p>We extend the model to account for the hierarchical structure of the
data, i.e., schools within districts, by using the <code>rma.mv()</code>
function from the <code>metafor</code> package and extending it with the
<code>random = ~ school | district</code> argument.</p>
<div class="sourceCode" id="cb3"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span><span class="va">fit_metafor</span> <span class="op">&lt;-</span> <span class="f