文档介绍：No, Monopoly Has Not GrownROBERT D. ATKINSON AND FILIPE LAGE DE SOUSA | JUNE 2021
Alarmists say the economy is experien11
Scheduled Passenger Air Transportation
%
%
335121
Residential Electric Lighting Fixture Manufacturing
%
%
481212
Nonscheduled Chartered Freight Air Transportation
%
%
333997
Scale and Balance Manufacturing
%
%
336214
Travel Trailer and Camper Manufacturing
%
%
517911
Telecommunications Resellers
%
%
327999
All Other Mise. Nonmetallic Mineral Product Manuf.
%
%
561330
Professional Employer Organizations
%
%
561510
Travel Agencies
%
%
447190
Other Gasoline Stations
%
%
Table 1: Top 20 industries with the highest percentage-point increase in the C4 ratio from 2002 to 201732
Table 2 lists the 20 industries with the highest concentration ratios in 201 7. Fourteen were highly concentrated in 2002, with six joining them by 2017. And of the industries with a C4 ratio above 80 percent, many of them were naturally concentrated. For example, it's hard to imagine why it would be more optimal for the guided missile and space vehicle industry, computer storage device manufacturing, or aircraft manufacturing to be less concentrated because of the enormous investments needed in research and development (R&D) and production to be successful. Others, such as HM0 medical centers and warehouse clubs, and home centers, may be concentrated, but faced competition from other industries (doctors1 offices and other retailers, respectively). Other industries on the list faced technological competition. Passenger car rental faced competition from ride-sharing and also from personal rental companies such as Zip Car.
Table 2: Top 20 industries with the highest C4 ratio in 2017 and their percentage-point change since 200233
NAICS
Code
Industry Description
C4 2002
C4 2017
PP
Change
522294