It's not that complexity is a direct cause of corruption, but that it gives corruption a place to hide. A complex system with incentives to abuse it will be far

It's not that complexity is a direct cause of corruption, but that it gives corruption a place to hide. A complex system with incentives to abuse it will be far more corrupt than a simple system with incentives to abuse it. You can a) reduce the incentives for abuse, b) reduce the complexity needed to hide abuses, c) both. Since government is basically power, the incentives to abuse that power always exist. So look for complex government systems and you will inevitable find abuse (if you can navigate the system's complexity).