, which we measured before treatment was assigned.&quot;
</p>


<h3>Usage</h3>

<pre><code class='language-R'>greek_data
</code></pre>


<h3>Format</h3>

<p>A data frame with 20 rows and 4 variables:
</p>

<dl>
<dt>name</dt><dd><p>The name of a Greek god</p>
</dd>
<dt>l</dt><dd><p>A prognostic factor</p>
</dd>
<dt>a</dt><dd><p>The treatment, a heart transplant</p>
</dd>
<dt>y</dt><dd><p>The outcome, death</p>
</dd>
</dl>



<h3>Source</h3>

<p>Hern√°n and Robins. Causal Inference. <a href="https://www.hs