In revising the Tinbergen Lectures I have expanded and restructured the material in an attempt to make the book more readable and more interesting. I have also tried to show more clearly its relevance to managerial and organizational practice. Some mathematical derivations have been moved to appendices. Certain sections that may be skipped in a first reading have been starred. Points that should be of interest to management include the nature and necessity of rank (4. 1, 4. 2, 4. 4) rank assignment by counting up or down (4. 3) defining an organization's task (6. 2) calculating the required...