GDP is a leading indicator. You can't fund European-style transit and social services forever if there's less money coming in.

Which is why is not a good indicator...

Government overspending, for example, increases the GDP.

	▲	gruez 6 minutes ago \| parent [-]
		No, GDP is a necessary but not sufficient condition for lavish government services. Yes, there are ways to juice GDP figures without actually having a functioning economy that can support lavish government services, but if your GDP is flat or declining, there's no way you'll be able to continue affording lavish government services.