Just think how much better things will be at Walmart once they unionize....../sarc
1. Bump the wages where necessary.
2. Incentivize management to actually do their job. (negative incentives work too)
I see it in my company all the time. We have upper management make bad business decisions, which they admit are bad business decisions, to protect their bonus.
As an engineer, that drives me nuts. I asked for, and got, my bonus to be based mostly on how the company performs and the quality of the product. If we spend more on overtime, but make double or triple that cost in profit, then it makes good business sense to do so.