ixed-effects corrections</span></span></span>
<span class="r-in"><span><span class="co">#</span></span></span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># We create "irregular" FEs</span></span></span>
<span class="r-in"><span><span class="va">base</span> <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/data.frame.html" class="external-link">data.frame</a></span><span class="op">(</span>x <span class="op">=</span> <span class="fu"><a href="ht