t_first <span class="op">=</span> <span class="fl">0</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>            vars     cond: 0    cond: 1 Difference t-stat     cond: 0</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1             y    0.32 (5) 0.47 (5.1)     -0.142 -0.326       1 (5)</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2            x1 0.046 (2.9) 0.17 (3.1)     -0.125 -0.487 -0.18 (2.8)</span>
<span class="r-out c