Are government workers more motivated?

In times if tight fiscal conditions, it is easy to criticize public employees. Civil servant have the reputation of being overpaid, underworked, lazy, unmotivated and enjoying too many benefits. I will not address all of this concerns here. I already covered overpaid, let us talk about unmotivated.

Using the World Values Survey, Sarah Smith and Edd Cowley find that public sector workers are intrinsically more motivated. To some extend this is not surprising, as one self-selects into the public sector when one is not that motivated by profits and money, but rather what public service stands for: serving others. But this does not apply to every country. The more corruption there is, the less motivated are civil servants. Indeed, in a corrupt government, public service takes a back seat to earning more money (or influence). How can one the explain the bad rap civil servants gets from private sector workers in the least corrupt economies? Maybe it is the public just reflecting its own values about work on the public workers, unjustifiably.