In sufficient quantities, money and power are fungible. Just ask Michael Bloomberg.
But in lower quantities, they are not. If you are the sheriff of a small town, you have a great deal of power, but even if exploit your power for money, you're not likely to become a millionaire.
If you earn $100K a year in Budapest, you're a wealthy man who can exert some real influence. If you earn $100K a year in Palo Alto, you're busy trying to conceal your poverty from your neighbors.
The sad fact is that humans are comparison engines. Absolute wealth is less important than relative wealth. Power, because it is relative to the people around you, is a more reliable source of happiness.
Of course, neither money or power is a useful goal. These extrinsic motivations are less productive than intrinsic ones like caring relationships, personal growth, and community involvement. And studies show that even those who achieve their extrinsic goals remain unhappy.
So if someone asks you, "Money or Power," the correct answer is "Neither." (Though if pressed, go for power!)
This post began as a comment on PandaWhale, which is fast becoming a go-to part of my information diet.