title: Stata drops variables that "predicts failure perfeclty" even though the correlation between the variables isn't 1 or -1?
body: <p>I am running a logit regression on some data.  My dependent variable is binary as are all but one of my independent variables.<br>
  When I run my regression, stata drops many of my independent variables and gives the error:</p>
  
  <blockquote>
    <p>"variable name" != 0 predicts failure perfectly<br>
    "variable name" dropped and "a number" obs not used</p>
  </blockquote>
  
  <p>I know for a fact that some of the variables dropped don't predict failure perfectly. In other words, the dependent variables can take on the value 1 for either the value 1 or 0 of the independent variable.  </p>
  
  <p>Why is this happening and how can I resolve it?  </p>