On this view the law’s goal should be to make a rule that gets the owner of the ballpark to think the way a single owner would when he decides what precautions to take. Making him pay for every window broken by his baseballs (whether or not he builds a fence) might do the trick; that would be known as strict liability. Making him pay only if he fails to think like a single owner—that is, making him pay only if he doesn’t build the fence, and it’s found that the fence would have paid for itself in the broken windows it would have prevented—probably would do it, too. That would be called liability for negligence.
Source: p 53, The Legal Analyst, Ward Farnsworth
I guess that here, in the = by means/reason of. In other words, the fence would've prevented the broken windows and the cost of fence is less than or equal to that of the windows.
Is this right? If so, please explain more about the use of in the here? Is there a term for it?