NEW YORK (Reuters) - New York City Mayor Michael Bloomberg's foundation is offering $9 million in prize money to other U.S. mayors in a competition aimed at generating ideas to improve city life.

Bloomberg Philanthropies, the billionaire politician's personal charitable organization, is offering five prizes to mayors of cities with populations of 30,000 or more: one grand prize of $5 million and four others of $1 million each. The awards are meant to fund the projects proposed to the foundation's judges.

"Cities, who are all having economic problems, have to do things better and cities are where mayors work day in and day out and they know what works, what the people want," Bloomberg said on Wednesday on the "CBS This Morning" program. "So we're trying to find out what's the best ideas."

U.S. municipalities have grappled with huge problems funding services for everything from trash collection to public education since the 2008 financial crisis and recession cut into their primary source of revenue: property taxes.

"Each mayor can have a different idea that's maybe transferable to another city, and we're all in this together," Bloomberg said. "So hopefully with this prize, people will focus on coming up with new innovative ideas that improve efficiency, improve the services, make government more responsive."

Mayors or their designated teams must reply by answering 24 questions on the foundation's website by July 16. The questions range from a 30-word description of the concept to whether the idea addresses economic or social problems or improves government accountability.

One question asks: "What's the headline on the cover of Bloomberg Businessweek in five years, after your idea is implemented?" Bloomberg Businessweek is the weekly magazine published by Bloomberg LP, the financial news and information company Bloomberg founded and ran before turning to politics.

Detailed submissions are due by September 14. The awards will be announced later in the fall.

(Reporting by Dan Burns; Editing by Eric Beech)