This article represents one of the first attempts at quantifying the level of corruption in India. This was made possible by the unique website ipaidabribe.com which invites people who paid a bribe to record their experience. By choosing a specific issue – identity verification by a police officer prior to issuing a passport – it was able to focus on a “harassment” bribe, that is a bribe paid for something a person was legally entitled to. Nearly half the persons using this website to report “passport verification” bribes were from the eight major Indian cities of New Delhi, Mumbai, Kolkata, Chennai, Bangalore, Hyderabad, Pune and Ahmedabad. This fact is, perhaps, less an indication of the concentration of corruption in these cities and more of the greater propensity of metropolitan residents to record their grievances. Of these cities, residents of New Delhi had to pay the largest amounts, and residents of Ahmedabad the smallest, in passport verification bribes.
A great example of what crowd-sourcing can do. The source is this article by Borooah (July 2012).