Hank Preston is the owner of Preston$$ Mechanics, an$$ auto$-$repair shop that does automobile servicing and repairs. Faced with an increasing number of$$ customers, Hank decides to revise his compensation policies in order to provide faster and better service. He feels that a$$ commission$-$based system, as opposed to the current$$ straight$-$time pay$$ system, will incentivize his workers to service more cars in lesser time. His$$ partner, Larry$$ Gomez, does not agree. He argues that the commission system will not significantly increase the number of cars being serviced per hour. In$$ fact, he feels that productivity and service quality might actually fall.$$

Which of the$$ following, if$$ true, will strengthen$$ Hank's claim?