It should be a living wage in whatever market the job is in. Executive pay should be capped to a multiple of the minimum employee wage and the average employee wage. No company should be able to make profit or pay dividends or bonuses unless every employee is making at least a living wage. If they do they are stealing the value of the labour.
I like that approach, but you'd have to deal with companies spinning off departments as separate companies on paper so that executives and average employees are paid by different companies and have different payscales. You'd have to do something like include any company that BigCo transacts with when calculating payscales for BigCo or something like that.
I would include every employee of every affiliated company and include suppliers and contractors. I would also make the benefits owed to part time employees higher than those owed to full time employees to incentivize companies to create full time positions. That way four people working four 25% time jobs each would be converted to full time employees.
I would also require that any offshore employees or contractors be paid the same as onshore employees.
There are extra considerations for being given shares in lieu of direct income that get complex fast, but could be done. The real problem is that shares appreciating in value lets them use the stocks for collateral without triggering any income taxes on the value.
I feel like using stock as collateral to get a loan should count as income or something that gets taxed. It's not because you technically haven't realized the gain, but you kind of have in practice.