t approaches.
Now that I’ve studied the literature I can summarize what I learned.</p>

<h2 id="reference-paper">Reference paper</h2>

<p>It took me a while to find the original derivations, but here they are:</p>

<ul>
  <li><a href="https://dspace.library.cornell.edu/bitstream/1813/32741/1/BU-640-M.pdf">S. R. Searle, 1978</a></li>
</ul>

<h3 id="the-simplest-form-of-the-equation-conceptually">The simplest form of the equation (conceptually)</h3>

<p>The advantage of REML estimate of the variance compone