Is America an Oligarchy?, asks John Cassidy (New Yorker 18 April 2014). He challenges what he calls the "alarmist" headline US is an oligarchy, not a democracy (BBC News 17 April 2014) reporting a recent study by Martin Gilens (Princeton University) and Benjamin Page (Northwestern University).
The study shows a small correlation between US policy and the opinions of the rich. No doubt this could be explained by the fact that the rich are more in touch with sociopolitical realities, which is probably one of the factors helping them to get rich in the first place. Correlation not causation? Yeah, right.
In any case, the supposed influence is asymmetrical. Even when the rich support some policy change, its chance of being enacted is less than 50%. But when the rich oppose some policy change, its chance of being enacted is less than 20%. Thus the rich appear to have an effective veto.
But a large veto is wielded by the political system itself. Only a small fraction of policy changes are enacted, and public opinion (whether majority or rich) doesn't make much difference. Obviously, the system itself doesn't like change. Now where have we heard that before?
Martin Gilens and Benjamin Page, Testing Theories of American Politics: Elites, Interest Groups, and Average Citizens (forthcoming Fall 2014 in Perspectives on Politics)