argument 51

wagner1985UID: 2838595

79. The following appeared in a magazine for the trucking industry.
"The Longhaul trucking company was concerned that its annual accident rate (the number of accidents per mile driven) was too high. It granted a significant pay increase to its drivers and increased its training standards. It also put strict limits on the number of hours per week each driver could drive. The following year, its trucks were involved in half the number of accidents as before the changes were implemented. A survey of other trucking companies found that the highest-paid drivers were the least likely to have had an accident. Therefore, trucking companies wishing to reduce their accident rate can do so simply by raising their drivers' pay and limiting the overall number of hours they drive."


The newsletter asserts that the increases in drivers’ paying may reduce the rate of accidents. To support this point, the author made a comparison between the rates in two different years. It revealed that after being granted a higher pay, the drivers are less involved in half the number of accidents as the before the changes were implemented. Based on this, the companies generally believe raising the drivers’ pay and limiting the overall number of hours they drive can reduce its accident rate. However, the argument has made a lot of faults, which made it less persuasive.

First and foremost, the assertion relied on the high correlation between the salaries of drivers and accident rates in experiences. But that cannot reveal a causal relation between them. It is probably because those high-paid drivers are experienced and well-trained so that have low accident rate. Thus increases in paying do not certainly exert a negative impact on the accident number. Nor do the surveys of other companies have validity to substantiate the power of lower paying, due to the reason mention above.

Secondly, from the viewpoint of the Longhaul trucking, the real numbers is incomparable between two years. Because it is really difficult to distinguish any power from the triple factors (paying, working hours, training standards) without anyone unchanged. Theoretically, any one the triple could positively affect the accident rate. The more paying may encourage drivers be more careful and more training lead to less mistakes, not to mention less working time itself halved the possibility of encountering misfortune.
So, without further investigation, the trucking companies have no enough reason drop any one of them and emphasize the effect of the other two.


Also，the traffic conditions the trucks often pass by, which is of great importance, are not mentioned from the statement. Provided the roads have been managed better than before in the second year, the overall traffic accidents would drop doubtlessly. Nothing should the company do will it enjoy this better result. So the outside condition, like road management, is the very factor could effectively take the place of the triple mentioned and avoid few misfortunes.

In conclusion, the two policies to decease the accident rate is not well supported. To corroborate that, the company should make a more rigorously statistic evaluation on the triple factors with some factors controlled. If and only if some relevant factors are fixed, could we estimate the effect of the other one with accuracy in different periods.