Introduction to Implicit Regression
  Statisticians usually restrict regression to model relationships that are explicitly defined dependent and independent random variables; this paper outlines the newly developed method of non-response analysis and rotational analysis for evaluating co-dependent variables without an obvious subject response. The concepts outlined challenge the notion of fixed effects; unity is included as a random measure (variable) ignoring the assumption of independence and the degree of separation is outlined which is a measure of model quality. 
Rebecca D. Wooten
stat.ME