The results of London's mayoral election won't be known until this evening, but it's not too soon to declare that they will be closely watched here, where resides a lively community of both common interests and of competition.

If the voters throw out Kenneth "Red Ken" Livingstone, it will be a repudiation of Mr. Livingstone's congestion pricing scheme, which is similar to the one that Mayor Bloomberg tried to impose on New York City. If Mr. Livingstone is replaced with a more capitalism-friendly mayor, such as the Conservative party's Boris Johnson, it could up the ante in a rivalry with our city, which lost out to London in the battle for the 2012 Olympics and is locked in a competition with London for status as the world financial capital.

Mr. Johnson's campaign Web site says that London must never forget that most businesses based there "can just as easily conduct their operations from New York, Shanghai, Dubai or Mumbai." He pledges, "It is essential that we continue to resist unnecessary regulation and over-taxation that would drive business and investors elsewhere. I am acutely aware of this threat, and if elected will use every strand of Mayoral power to fight against Labour Government over-regulation and over-taxation."

Mr. Johnson was born in New York and lived here until he was 5. Like Mr. Bloomberg, who owns a home in London, his professional background is the news business. It would be ironical indeed were he to win the election and present the city of his birth with a more formidable international competitor. Mr. Bloomberg yesterday announced shrinking city revenue projections with the words, "Everybody in this city should pray Wall Street does well."

Much as New Yorkers will agree with him, Mr. Bloomberg well knows that prayer alone is no substitute for an economic development strategy. Whoever wins London's mayoral election will have a term of office outlasting Mr. Bloomberg. And whoever succeeds Mr. Bloomberg in New York will have to give thought to how our city can succeed in a world in which a mayoral election an ocean away may have a profound effect on our own future.