Average hourly employer cost for occupations offered bonus plans, by number of workers in establishment, private industry, March 2000 Cost Per Hour Under 100 workers 100 to 499 workers 500 workers or more Referral bonus $0.04 $0.14 $0.06 Hiring bonus $0.09 $0.04 $0.08 Retention bonus $0.10 $0.09 $0.13