Investigators are conducting a cohort study to determine whe

Investigators are conducting a cohort study to determine whether women exposed to high levels of exposure to electromagnetic fields are more likely to be depressed.   Low socioeconomic status is associated with 1) living near power lines and 2) depression. What type of bias or error is most likely to result?

a. Selection bias

b. Nondifferential misclassification

c. Ecologic fallacy

d. Confounding

e. Random error

Solution

c. ecologic fallacy