If it takes the mechanic longer than that, too bad for him because he’s only getting paid the billable hours (if that happens enough he needs to consider another line of work).

What you’re describing is a bill-by-service arrangement. That’s different from a strict bill-by-time arrangement. Lawyers don’t estimate their time and stick to that estimate the way a mechanic might – they’re supposed to only bill for the time actually worked.

The reward for efficiency isn’t fraudulent billing (which Gary does if billed by time rather than service); it’s a better reputation which draws more clients.

When I take my car in for service, the service manager looks on a chart to see how long the service I need is supposed to take, and he bills me that amount for labor. But that isn’t necessarily how long it will take.

If it takes the mechanic longer than that, too bad for him because he’s only getting paid the billable hours (if that happens enough he needs to consider another line of work). Sure, complications happen. And sometimes things go smoother than usual. These things average out.

On the other hand, I had one mechanic who was an expert at finding the most efficient way to do things. Sometimes a task that the book said was 4 hours was only 2 for Gary. Gary still got paid 4 hours for the task, however. He was rewarded for his efficiency. The dealership was happy because that allowed them to do more work over the course of the day. The customer was happy because he got his car back earlier. And sometimes Gary would get paid for a 12 hour day when he only actually worked 8.

Now, I have no idea whether lawyers have a big book of “how many hours is X legal task supposed to take.” But I bet any law firm that has been in business very long has a very good idea of average time for common things like will writing and traffic ticket defending. And if some lawyer has a more efficient way to get out of a traffic ticket, allowing to process substantially more than his colleagues? More power to him!