Mayor Michael R. Bloomberg today announced the Bloomberg PhilanthropiesMayors Challenge, a competition in which all U.S. cities with populations of 30,000 or greater are invited to submit their boldest and most replicable ideas for improving cities in any of a number of ways. Bloomberg Philanthropies will award one $5 million grand prize and four $1 million additional prizes to the five cities with the most innovative ideas.

In order for an idea to have resonance, Bloomberg said, it should be something new and visionary with potential for impact and feasible to implement. The Mayors Challenge is a competition to inspire innovative solutions to address serious social and economic issues; enhance accountability to or engagement with the public; improve customer service for residents or businesses; or, create efficiencies that make government work better, faster, and cheaper.

Bloomberg pointed to Plan NYC, the city’s sustainability initiative that he said has resulted, among other achievements, in reduced greenhouse gases and fewer asthma-related visits to emergency rooms, and Chicago’s implementation of a 311 system, a program to help Chicago citizens access city services more efficiently, as examples of the type of innovative proposals the program seeks to highlight.

“Every day, mayors around America are tackling increasingly complex problems with fewer and fewer resources,” said Michael Bloomberg in a statement. “Our cities are uniquely positioned to inspire and foster the innovation, creativity, and solutions needed to improve people’s lives and move America forward. The Mayors Challenge creates an opportunity for mayors to champion their boldest ideas – and to have them take root locally and perhaps spread nationally.”

The competition will encourage local officials to stretch their thinking on how to effectively address urban challenges, noted ULI chief executive officer Patrick L. Phillips. “Cities around the nation are grappling with a variety of growth-related issues, including economic and demographic shifts as well as environmental concerns. In the post-recession economy, local officials are compelled to be evermore creative in coming up with strategies to keep their communities prosperous and competitive. The Mayors Challenge is a wonderful incentive to spur the best thinking and best outcomes.”

According to the initiative’s website, interested cities must declare their participation in the program by July 16, with final idea submissions due September 14. In late 2012, the top 20 finalists will attend the Bloomberg Ideas Camp and will then refine and submit their ideas. The five winners will be announced in spring 2013.

A selection committee, co-chaired by Shona Brown, senior vice president and head of Google.Org, and Ron Daniel, Bloomberg Philanthropies board member and former managing partner at McKinsey & Company where he is still active, will help Bloomberg Philanthropies select the winning cities.

Watch a video about Bloomberg Philanthropies’ Mayors Challenge.