There are probably three factors that would influence the ability to make effective decisions - do they know what the problem is; are they able to fix the problem; and are they willing to fix the problem.
Do they know - hard to argue "they" don't know, although ideology could lead certain leaders to ignore or deny the validity of demand-side growth.
Are they able to - this used to be a no-brainer. not as certain anymore, but still a generally safe bet they are able.
Are they willing to - this is a major problem. 1) powerful vested interests supporting supply-side growth, 2) the loss of power that comes from relying on demand-side growth