Daniel H. Pink, Drive: The Surprising Truth About What Motivates Us (New York: Riverhead Books, 2009).
In Drive, Daniel Pink takes us through some interesting research into what motivates people and finds that autonomy, mastery and purpose have more influence than rewards and punishments. Rather than suggest that these elements (autonomy, mastery, purpose) apply universally he is careful to suggest that in some circumstances, and for some people, intrinsic rewards may be more powerful than increased profit.
The author does not write much specifically about the law firm environment (other than to highlight the lack of autonomy and control) but I appreciated his insights into the potential for more inclusive environments. The advantage of flexible work arrangements (and therefore a more diverse legal profession) are clear from the studies he cites and provide some inspiration for anyone interested in rethinking the organization of legal practice today.
For a quick overview of the book, check out the RSA Animate of his Ted Talk found here.