To me, the word "economy" covers all the sciences and techniques facilitating the comprehension of a system or an activity (ie individual, society, company, living organism...).
Economy can use mathematics, social sciences, history, psychology, ethnology... you name it.
That's what makes its charm, and the reason why I chose this path instead of more hemiplegic studies (back then, it was either "sciences" or "literature").
Like politics, economy is fundamentally noble, but reality a slightly different matter. We shall win over nowadays depression only by opening ourselves up to economy, not by trying to elude it because we forgot what it means for the future of this planet (see "This is not a financial crisis").