Merck's income as a percentage of revenue has averaged 27.51% over the last 5 years, higher than its competitors' average of 23%. Merck's revenue per employee was lower in recent years due to an 81% increase in employees from a merger, but this metric should rise as Merck cuts almost 20,000 jobs by the end of 2012. Merck had a lower return on investment in 2009 because of a large acquisition, but it has shown steady high returns on assets, demonstrating effective management.