Is your claim that there is a substantial overlap in <characteristic of interest> between the two firms or that the distribution is the same? Not being from the USA my knowledge of the two companies is limited but I believe they serve different market segments and sell different product mixes although they're both basically big box superstores. While workers at either are most definitely members of the proletariat I imagine tenure of employment and highest degree are both higher at Trader Joe's than Walmart.
The American variant of classism is more amusing than average to be sure.
I don't believe that there is a meaningful difference in employment pools between WalMart and TJ/Starbucks but I acknowledge that many customers of Starbucks strongly feel differently.
The American variant of classism is more amusing than average to be sure.