May 1991Also issued as an M.S. thesis, Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, and Sloan School of Management, 1991Includes bibliographical references (p. 131-132)The thesis examined the effects on competition of deregulation in the airline industry by analyzing changes in concentration over the ten-year period 1979-1989 in two sets of origin-destination city-pair markets: the top 100 markets in which the most passengers traveled in 1989, and the top ten markets to and from each of fifteen dominated cities. Concentration levels were significantly lower in the top 100 markets in 1979 than in 1989. Average concentration levels in the 150 markets out of the dominated cities were only slightl...