The original plan for this volume was to publish a handbook in which each essay was twenty-five to thirty typed pages. This length is substantially under that of, say, a Journal of Economic Literature survey, and so the intent was not to be as comprehensive in referencing the literature as this more standard survey, but for the author to describe and discuss an area highlighting the main ideas and contributions in it. Many of the authors stuck to this early game plan, but some did not owing to the nature of the subject matter surveyed, or to personal style. In addition, the last of the manuscripts to be completed received less intensive editorial cutting, because I, mistakenly as it turned out, did not think I had the time to do it. Thus, the articles vary somewhat in length and in the length of their reference lists.

For a variety of reasons including my move from College Park, Maryland to Vienna, the “development time” of this volume has been lengthier than most. The earliest of the essays were completed in 1992, and even the latest in 1994. Thus, some recent articles or books that the reader would expect to see referenced may be missing, not because of the author's negligence, but because the essay was finished before the work appeared. (A single set of references for the entire manuscript is at the end of the book.)