One measure of competition in an industry is via Concentration Ratios. These generally take 2 forms:
In the U.S., these data are collected and measured by the Census Bureau's Economic Census (available every 5 years only); concentration ratios from the 2017 Economic Census is part of the Establishment and Firm Size data series, which was released beginning in November 2020.
1) The easiest way to find them is to go to Data.census.gov, and search for "concentration," then hit the button to View All Tables." That should pull up the most recent available tables, now from the 2017 Economic Census (as of Nov 2020), as well as prior years. The 2017 Data is initially available in a report titled: Selected Sectors: Concentration of Largest Firms for the U.S.: 2017. This should display the table at the 2-digit Sector level of the NAICS industry classification. If you want lower level industries, click the Codes button in the top menu, select Industry Codes, and select the box for the 2-6 digit level of detail you want, then close and the table will reformat.
For the concentration ratio percentages, see the column entitled "Sales, value of shipments, or revenue of largest firms as percent of total sales, value of shipments, or revenue (%)". This shows the CR % for 4,8,20, and 50 firms by NAICS industries from 2 to 6 digits of the hierarchy. The following column will show the Herfindahl-Hirschman Index for the top 50 firms.
For 2012 and prior years, the tables are organized by major NAICS industry groupings, so you should be able to browse for the sector that contains your lower level industry. (Note: as you scroll down the results pane on the left, you may see a "Load More" button which you'll need to hit to see the full list). Open your desired industry to scroll through and explore the data. Hit the "Customize Table" to see a menu bar of options, including "Download."
Most industry grouping tables will show the n-firm (4,8, 20, and 50 largest firms) percentages of revenue earned; the Manufacturing tables show the share of "total value of shipments and receipts for services" instead, and also include the Herfindahl-Hirschman Index (HHI) figures for the 50 largest companies.
2) You can also use a shortcut if you know the specific industry code you want. For example, if you search: concentration 311111, you'll pull up a table with just that NAICS code.
Concentration ratio data from the 2017 Economic Census were released starting in November 2020. | Release schedule
Tools used by economists and regulators to measure industry market concentration.
Two federal agencies have primary responsibility for antitrust law enforcement in the U.S. There are any number of entities that have jurisdiction in other countries. You may find economic analyses or legal filings on past or present mergers and acquisitions that shed some light on the competitive nature of individual industries.
The Census Bureau is one of the best sources for economic & demographic data.
In eStatement Studies you'll find Financial Ratio Benchmark (FRB) figures, broken down by US Region and revenue quartile, for a very large number of industries. Search or browse by NAICS industry codes.
The North American Industry Classification System (NAICS) is used to organize industry information. It's designed to produce common industry definitions for Canada, Mexico, and the United States. It is a hierarchical classification system, offering five levels of detail. Codes are assigned to an industry based on products and services provided by the industry.
Industries are represented by a six-digit number. The first two digits designate the economic sector: manufacturing, agriculture, wholesale, retail, professional services, etc. The subsequent digits designate subsectors and industry groups.
Each digit in the code is part of a series of progressively narrower categories.
Example:
72 - Accommodation and Food Services
722 - Food Services and Drinking Places
7225 - Restaurants and Other Eating Places
722511 - Full Service Restaurants
The Standard Industrial Classification (SIC), an earlier U.S. system, is still used by some sources.