Per your example, can we assume the executive makes $200k, after deductions and the administrative assistant makes $50k after deductions for easy math?

The executive pays $78k in taxes. 
The assistant pays $5k in taxes.

For that additional $73k in taxes paid by the executive, she gets a "subsidy" of a little less than $1200 in our hypothetical example. Contribute an extra $70k+ and get a little more back on the other end. 

Who, in this example, is subsidizing who?