Few researchers have found significant correlation between a stock's past and future performance, however.

But most of the research finds little correlation between spending and quality.

One Australian study appears to have found such a correlation.

Yet when researchers track the data within individual countries over time, they find a negative correlation.

A number of studies found a positive correlation between video game play and increased violent behavior.

Using data from 1,000 1988 annual reports, the survey found a close correlation between industry performance and pay increases.

The study also found a correlation between poverty and mortality rate.

Studies have also found a correlation between domestic violence and increased use of abortion.

No study has found a simple correlation, for example, between testosterone levels and crime.

The two were not able to find a significant correlation between the content of one's dreams and the day's events.