Question 6: In a mature industry, profitability numbers generally fade, industry becomes saturated and turnover drips. What actually happened in US-based-retailing industry? Why did profit numbers not fade for this industry?

Decade	Industry NPM	Industry ROA	Industry ATO	Industry Concentration*
1971-1980	2.1%	14.3%	3.03	219.63
1981-1990	-1.4%	12.6%	2.51	234.13
1991-2000	-8.4%	10.8%	2.25	242.08
2001-2010	-4.9%	10.2%	2.20	436.52
2011-2020	2.0%	13.5%	2.10	570.58
Average	-2.1%	12.3%	2.42	340.59

Table: S-C-P analysis (Retailing industry)

Data source: WRDS; Data Management: Stata

Key Procedure: a. Fama-French 48-industry categorization was used to define industry.

b. Basic EPS was used in NPM calculation.

c. Instead of the popular top-4 or top-5 retailer based HHI, we calculated the index for the whole industry.

*Note- Industry concentration was calculated using H-H index.