Proportional election = parliamentary corruption?

First I acknowledge there are many cause of parliamentary corruption.

Lax law enforcement (pre KPK) is certainly important factor. And so is the possibility of tradeoff between justice and money. The more money (from corruption) you have, the more likely you can hide evidence of wrongdoing.

But the path to become MP is very much up to discretion of party leader. At which province you will be put forward and at which rank number.

The discretion is basically something the party leader can disperse as he/she pleases since most party campaign not on individual MP but on a national figure and party history. And money is certainly one way to please a person. If a prospective MP has to pay significant to get his/her seat then the investment need to be recoup.

The incentive would be much less in district system where people choose a person. Each party has to put forward the most prospective candidate to win; a primary system where internal party election decides on candidate is even better.

Anyway, Indonesia certainly needs better campaign finance system so we know who give to party/candidates and how much.