Don Boudreaux posts in his excellent blog Cafe Hayek
…from page 211 of Gary Becker’s and Guity Nashat Becker’s 1997 book,The Economics of Life:
Voting out crooked politicians and punishing people in business who illegally influence policies discourages corruption. Reform movements that come to power often make good for a while on their promises to clean up the process and eliminate corruption. During such crackdowns, businesses and other rent-seekers must rely on campaign contributions and other legal ways to influence outcomes.
But corruption always reemerges wherever governments have a major impact on economic conditions. The momentum behind reform movements peters out as politicians, officials, and companies become tempted once again to risk exposure and disgrace by giving and receiving bribes and engaging in other corrupt acts.
There is only one permanent way to reduce undesirable business influence over the political process: Weaken the link between business and politics. It is essential to simplify, to standardize, and especially to eliminate many of the regulations affecting economic activity.