It's obviously less than it could be if the company's PROFITS (outweighing costs like employee wages and benefits) were $15.7 billion in three months. Theoretically, Wal-Mart could take a profit of only $8 or $9 billion in three months (a substantial amount in any economy) and reinvest the rest of those profits into higher wages and better benefits so that Wal-Mart employees don't require as much public assistance.
Why doesn't trickle down theory work in practice?
That's the whole point of this thread. Trickle down theory is the
only way any capitalist free market system works. The alternative would be to have authoritarian or totalitarian Marxism, Maoism or Communism, controlling all means of capitalism.
What you are doing with your Walmart example, is taking the data after the fact and determining what is "fair" for Walmart to make as a capitalist. The glorious and beautiful thing about free market and free enterprise capitalism is, if you believe this is a better capitalist model, you are free to go out there and start your own rival company and put Walmart out of business. The employees of Walmart would much rather do the same work for your company and make twice the pay, so you'd have no problem hiring people.
The problem is, you could never catch up to Walmart as they generate twice as much profit as you each year, thus have twice as much to reinvest. Plus, you are going to lose money in the beginning, until you can match the presence and buying power of Walmart nationwide. Your formula would be a major hinderance as you struggled to try and catch them. But... let's say that you had deep pockets and could afford to keep your business afloat long enough to catch Walmart and put them out of business... you show a much more modest $8 billion profit and some jerkwater liberal comes along and arbitrarily decides you are making "too much" profit, and you "don't deserve" more than $2 billion per year. See where this is going?
Capitalists are not in business to ensure income equality. You don't go to work and earn a paycheck with the motivation and objective of "making everything fair for everybody." A capitalist is trying to make as much profit as possible, and you are trying to earn as much payday as possible. The "good" thing about this is, the more profit the capitalist makes and the more paycheck you earn, the more taxes are paid into the system.