I enter into this idea knowing that it is far fetched that any politician would allow themselves to be a party to such an agreement. However if the politician had no choice; that is if it was submit or not get the media exposure then they might not have a choice.
The idea is this. Prior to an inteview, a politican would enter into an agreement with the interviewer or their organization who would back the development of an agreement based on the promises and factuality of the propective office holder.
A net worth analysis of the prospective office holder would be done and then a derivative contract would be drawn up detailing what a promise was worth based on percentage of net worth or in additon future net worth.
For instance if a politician made a promise or statement that if he were elected the unemployment rate would not exceed 8% as defined by the Department of Labor. He would then be required to back that statement with 30% of his net worth, and possible future earnings.
At the conclusion of an interview the contract would be a derivative security that could be marketed to prospective buyers to cover the cost of development and make a profit for the organization that conducted the interview.