Well, it was never the intention of Alfred Nobel to have a prize for Economics. The so-called "Nobel Memorial Prize in Economics" was established after a large donation from the Bank of Sweden in 1968, but has been regarded by many (including Nobel's grandson) as an inauthentic award.

The Nobel price for economics was awared to quite a few mathematicians.

Leonid Kantorovich won it for applying his results in Operations Research [1] to planning the Russian economy.

John Nash won it for .. of course .. Game Theory.

[1] He proved criteria for the convergence of the Newton Method and quite a bit more. Those results are applied really everywhere nowadays.