If a faculty member isn't writing as much as he or she "ought" to be (define that as you will), what incentives might help move the faculty member toward scholarly productivity? Of the bunches of carrots and sticks that law school deans (and research deans) have, summer research grants seem the most common. Less common is an "opt-in" reduced teaching load in return for enhanced scholarly productivity. My school is in the beginning stages of our first experience with such an opt-in program.
The basic idea is this. Several years ago, our faculty adopted a "statement of expectations" for itself. Those expectations include the publishing scholarly works such as articles in law reviews, normally at least one such article or its equivalent every other year (or books at greater intervals). In return for publishing at a rate "faster" than baseline (i.e., one article or its equivalent every year, instead of every other year), a faculty member can receive a 2-1 teaching load (or approximately 9 credits per academic year). Otherwise, our standard teaching load is 2 courses each semester (or approximately 12 credits per academic year). A faculty member who does not in fact produce by a certain date at the faster rate must then "give back" his or her course relief in the form of an overload in a subsequent year. There are guidelines about what "counts" as an article (in terms of length and venue of publication), and pockets of decanal discretion to deal with unusual circumstances.
At schools where all faculty members are actively writing (ummm...are there any faculties without some dead wood?), there's no need for this type of program, and many of them indeed already have 2-1 teaching loads. And at schools where teaching resources are already stretched, this type of program might not be feasible.
Nevertheless, at my school the program seems to be working well so far. Some advantages of the opt-in program are that (1) it is available to all faculty members, and (2) the standard is susceptible to measurement. There are no ex ante decanal decisions about who is (or is not) "productive," and in most cases, it will be abundantly clear whether a faculty member has (or has not) met the output expectation. Disadvantages of the program are that (1) there is a built-in bias in favor of quantity over quality; (2) the program takes some great teachers out of the classroom; and (3) it makes no distinction between excellent articles and mediocre ones (our tiered summer research grant program does some -- but not all-- of that work).
So far, everyone who has opted into the reduced teaching load program seems happy with it, and is well on-target to meet the productivity expectation.