P>In Ophthalmology Management’s 1999 income survey a change in gross correlated to the population of the practice locale. Of the doctors practicing in large communities (more than 100,000 residents), two out of three reported earning a lower gross in '98. Of the doctors practicing in smaller communities (less than 100,000 residents), two out of three did better in '98.

The explanation may lie in the fact that these groups also correlated by age and number of hours worked. The implication is that younger doctors (working longer hours) are favoring practicing in smaller communities.