Table 4. HMO and Market Characteristics for IPAs, by Quartile of Competition.
| HMO and Market Characteristics | Competition Quartile | |||
|---|---|---|---|---|
|
| ||||
| Bottom | Low | Moderate | High | |
| Number of HMOs | 2.89 | 5.81 | 9.69 | 16.32 |
| Average Enrollment (in Thousands) | 39.0 | 34.1 | 49.6 | 56.2 |
| HMO Market Penetration | 0.10 | 0.13 | 0.16 | 0.18 |
| Per Capita Income (in Thousands of Dollars) | 15.54 | 17.36 | 19.45 | 20.89 |
NOTE: HMO is health maintenance organization. IPA is individual practice association.
SOURCE: Research by Feldman, R., Wholey, D., and Christianson, J. for this article, 1996.