While your major definitely influences the kinds of jobs that you can get, your starting salary and potential for growth will be determined by what kind of work you do, not exactly what you major in.
According to the Georgetown Center for Workforce Education (who based their analysis on the American Community Survey, a representative sample of the American population) recent graduates (< 5 years out of college) who majored in business averaged $37,000 per year; for computer science, it was $50,000. Engineering varies based on the type of engineering you do; civil engineering majors averaged $50,000 whereas electrical and mechanical engineering majors averaged $58,000.
Potential for growth is difficult to measure. One, because it completely depends on what you decide to do later - do you stay an individual contributor, or do you go into leadership and management? Two, because “business” (and “computer science” to a certain extent) is such a broad field that you can hold any kind of role in it later. The Wall Street Journal has a salary survey that looks at mid-career salary growth using Payscale data (not the best, but better than nothing). At mid-career, the middle 50% of business management majors made anywhere from $51,500 to $102,000 per year; engineering varied based on field, but the middle 50% of mechanical engineering majors made from $76,200 to $120,000 per year; and the middle 50% of computer science majors made from $74,900 to $122,000 per year.
Most desirable, enjoyable, and difficult are really subjective. If you’re asking for my personal opinion about the major, I would say that computer science is the most enjoyable, followed by business and then engineering. About the job? That totally depends on what you do, and is also dependent on the kind of engineering you do. I’m sure designing city public works is way different from designing new transistors, or rocket ships, or cars. Also, there’s a lot of fluidity between the fields - an electrical engineering major can get a lot of the same jobs as a CS major in software development. “Business” isn’t even really a field so much as it is just a process, and a business major could be doing any number of things that could either be fun or boring.
I think on average, business is likely to be an easier major than CS and engineering. Although at most schools engineering may be more difficult than CS, it kind of depends on the school and how rigorous the major is at that particular school.
Opportunities for internships? Eh. Again, “business” is such a huge field that there are a myriad of internships in it. However, the top internships - at the best consulting and banking and financial companies - are going to be very competitive and very difficult to get, partially because anyone in most majors can compete successfully for them (especially coming from an elite school). You’ll be competing with the economics majors and all the social science and humanities majors who decided they wanted to go into consulting or investment banking. There’s a smaller number of internships in CS and engineering, but there are also a smaller pool of people who can successfully compete for those. Also, CS is exploding and there are so many opportunities directed towards increasing the CS workforce right now. I would imagine that electrical engineering is probably the major that’s easiest to get an internship in right now, followed by CS, followed by other engineering areas.
Sources:
https://georgetown.app.box.com/s/og6p8y9x1yeacejk1ci0
http://online.wsj.com/public/resources/documents/info-Degrees_that_Pay_you_Back-sort.html
