">
<dt><code class="code">date</code></dt>
<dd><p>Start date of the quarter for the observation.
</p></dd>
<dt><code class="code">y</code></dt>
<dd><p>Observed quarterly revenue.
TODO: Determine units (probably millions of USD?)
</p></dd>
<dt><code class="code">lag_quarterly_revenue</code></dt>
<dd><p>Quarterly revenue (<code class="code">y</code>), lagged 1 quarter.
</p></dd>
<dt><code class="code">price_index</code></dt>
<dd><p>A price index
</p></dd>
<dt><code class="code">income_level</code></dt>
<dd><p