[appleiigs]

I have a finance career and am also the technical partner of a startup. This answer mirrors my opinion. Economics is nearly 100% theoretical and not useful at all for entrepreneurship which is nearly 100% practical.

Most other answers here are confusing finance or accounting or business-sense for economics... which shows how little they know about economics. And by the way, formal finance and accounting also has little value for an entrepreneur too (just hire an accountant).

My startup partner has a background in marketing and is doing great building the business (while being inept in finance, accounting, technology or economics). If you aren't familiar with marketing, as said above, it's all about knowing your customers.