If you want to understand why Indonesia seems to be turning its back on fossil fuels faster than its richer neighbor Australia, you could do worse than look to the wit and wisdom of David Lee Roth.

"I used to have a drug problem,” the hard-living Van Halen singer is supposed to have once said. "Now I make enough money.”

That’s as much a lesson about fiscal policy as it is about rock ‘n’ roll. Middle-income countries like Indonesia simply don’t have the money to waste on indulging costly habits like supporting a fossil fuel industry on the brink of rapid decline. Richer nations, like Australia, can be more indulgent.