The Handbooks in Economics series provides the various branches of economics with definitive reference sources, suitable for use by professional researchers, advanced graduate students, or by those seeking a teaching supplement. With contributions from leading researchers in the field, each volume presents an authoritative, self-contained survey of the topic under examination. With over 110 volumes in the collection, the handbooks are more highly cited than any other economics journal. They have an active shelf life and volumes remain significant in today's environment. A number of our editors and contributors are recipients of the Nobel Prize in Economic Sciences, including founding series editor Kenneth Arrow and 2013 winners Lars Peter Hansen and Robert J. Shiller.