Sure, there are some formulas in economics, but 99.99% of the time you are not going to prove anything mathematically and you are just looking up a formula written by somebody else. On the other hand economics has a huge amount of stuff that is not covered by mathematics at all.
It is disheartening to see so many people wasting so much of their potential by studying CS when they know they will get into software development anyway. Rather than racking education costs they could be earning money and gaining experience.
I have been constantly hiring for the past 15 years and I have learned to stop caring about CS. Real world experience is worth more than comparable time spent studying CS.
The only reason I may prefer a candidate with a degree is because it takes a lot of work and perseverance to stick to the goal of earning the degree, but I almost don't care what kind of technical degree you have earned.
One more point, it is not like academia is the only place where you can learn CS! In some areas of knowledge and at bleeding edge of it you may need access to people, but basic CS knowledge that can ever be even potentially useful at development work is all well documented in a huge selection of very good books.
You can pick them up and learn.
Good developers treat learning as part of their work, and it doesn't matter if something was not taught at school -- if they notice they are missing some knowledge they will just learn it.
If you need to study something I think it is better to study something orthogonal to what you are going to be doing. This can help create unique profile for you as a developer.
For example I have studied theoretical math and over the years I came to conclusion that was much better choice than going to CS. I have learned logical thinking and dealing with complex abstract problems. I have learned most of the CS stuff anyway while doing my work but I would probably never learn most of what I learned in math.
Other good directions of studies would be philosophy, visual arts, management, accounting -- you see the picture. Any of these could provide you with an edge as a developer for particular set of problems.