Joe works at WidgetCo and makes $60,000/yr. His loaded costs are a little over $100,00/yr.
WidgetCo pays this because his skills are worth about $125,000/yr to them, so it's a great deal.
At this point, if you are a well-meaning, but rational cherub, what is the highest rational price to pay to get Joe working again? I'm guessing anything up to $125,000.
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But that's not the end of our grossly simplified model. We also have the fact that Joe spends his paycheck on niggles. He fucking loves the shit out of niggles. As he consumes $60,000/yr of niggles, he personally pays for 1/2 of an employee at the niggle factory (and that guy spends his money on something too...)
So now we have to recognize that if Joe loses his job, there's going to be a negative ripple effect, and if Joe gets a job, there's a positive ripple effect.
So now, as a well-meaning, but rational cherub, what's my highest rational price? Well.. at this point I'd probably call in an economist to help me figure it out, but it's clearly more than $125,000/yr... it's likely close to $200,000/yr.
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And now somebody hands me a "stimulus" proposal, and it turns out that I could create a job for Joe for about $150,000/yr. So let's see... $200,000/yr of value for $150,000/yr... sounds like a great investment to me! Very good value for money, even if it does lead to an annoying headline indicating "$60,000/yr jobs cost silly cherub $150,000!"
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Obviously this is grossly glossed over (I didn't even mention the obvious fact that if people are buying widgets, they must provide value), and actual models of costs and benefits of various scenarios are quite complex, but I simply meant to demonstrate that simply dividing the total cost of a package by the number of jobs is silly, and misses the point widely.