Pb. Oneill, THE TREND OF AGGREGATE CONCENTRATION IN THE UNITED-STATES - PROBLEMS OF SCOPE AND MEASUREMENT, The American journal of economics and sociology, 55(2), 1996, pp. 197-211
Data on aggregate concentration in the United States economy for the y
ears 1978 to 1987 are analyzed. Economy-wide aggregate concentration d
ecreased during this time period. Aggregate concentration increased in
the retail trade, electric and gas utilities, and transportation sect
ors but decreased in the manufacturing and life insurance sectors. Iss
ues surrounding the appropriate measurement of aggregate concentration
are discussed.