[PGR88]

Bono learned enough about economics to accumulate a net worth of about 700 million dollars.

So it had nothing to do with U2 song-writing?

[Rockingham]

For successful entertainers, the hard part tends to be knowing how to keep and grow their earnings into substantial wealth. That is where sense about money and economics is required, a set of skills that is far apart from being a good songwriter and performer.