[dragonwriter]

> It is a labor subsidy,

No, it's not, it's an anti-subsidy, because money is taken away from workers for getting paid by an employer, increasing the amount an employer needs to pay.

> because Wal-Mart is not having to pay their workers a living wage

WalMart wouldn't have to pay a living wage without it, either. Public assistance programs (aside from work requirements and the cost of lost benefits from failure to comply) actually increase market clearing wages, they don't decrease them.

> because they can simply tell their workers to sign up for public assistance

The people involved can sign up for public assistance with or without working for WalMart; further, they lose benefits due to mean testing based on outside income, which means WalMart has to give them >$1 of take home pay to get labor they would be willing to trade for $1 of net income increase.