Page:A White Paper on Controlled Digital Lending of Library Books.pdf/36

 design features that may reduce risk and enhance the fair use position, primarily by enhancing the argument that CDL does not pose an undue market harm. These design elements attempt to make CDL mimic even more closely the physical environment and attendant friction reuse, as well as the security limitations that physical lending currently requires.

One way is to introduce additional artificial “friction” into the system, for example, is by extending the time between digital lends, more closely mirroring how physical books are lent and returned. For books that would typically take 24 hours to make their way back on to the shelves after being returned, that might be an appropriate waiting time for digital copies as well. For reserve materials that rapidly move in and out of the shelves with little wait, a shorter period may be appropriate to mimic the realities of a physical lend. Libraries may even want to take in user geography—if a user borrows a book while located further away, add more time in between the next loan than if the user is located next door—or other factors that have historically slowed the flow of physical works.

A conservatively designed CDL system could also introduce characteristics that mimic physical degradation. For example, a library might introduce lending limits based on library experience with physical lending. If a physical book could be expected to circulate 2,000 times before it degrades, the library could place the same limit on circulation of the digital copy. For many books, this could pose little practical challenge. Large research libraries hold many books that have circulated very seldom in print, and so for many obscure materials ever hitting a maximum loan threshold may be unlikely (though we recognize, digital availability may itself drive lending). For such an implementation, it would be important for libraries to develop good data on how long an average book actually circulated before it degrades to the point it can no longer be used. Library experience and publisher expectations seem to diverge significantly on Page 36