><strong>reg666:</strong> =1 for region 6, 1966</p></li>
<li><p><strong>reg667:</strong> =1 for region 7, 1966</p></li>
<li><p><strong>reg668:</strong> =1 for region 8, 1966</p></li>
<li><p><strong>reg669:</strong> =1 for region 9, 1966</p></li>
<li><p><strong>south66:</strong> =1 if in south in 1966</p></li>
<li><p><strong>black:</strong> =1 if black</p></li>
<li><p><strong>smsa:</strong> =1 in in SMSA, 1976</p></li>
<li><p><strong>south:</strong> =1 if in south, 1976</p></li>
<li><p><strong>smsa66:</stron