I've been hunting for data analysis jobs for awhile. I even put a few apps in for corporate research gigs. The more I've looked into this field, the more confident I am that I can do this kind of work. That hasn't translated to getting past HR departments but I'm making slightly more progress of late.
One thing that has come up in my informational interviews around the area, is the idea of doing data analytics consulting. This could be anything as simple as sales data, association analysis (what stuff do people buy together, think Amazon suggestions), or even something as complicated as survival analysis (how long to customers stay around, why do they leave). I can program SQL and R. I can make excel dance. I can even program macros...on a non-Mac. Macs suck for programming macros. Honestly, you can do all that too. There are several websites out there that will teach you. But people don't want to do that and are willing to pay someone like me to consult on this for them.
This terrifies me on a number of levels. I'm sure I can do the work itself. It's the idea of owning my own business that scares me. I will freely admit to having no business acumen. I have no idea how to go about this. I suck at selling stuff. How do you go about finding your own free-ranging health care and retirement fund? Taxes?! I hate cold-calling and that's really the main way to find new clients. Referrals help but you need to start somewhere to get referrals.
Sometimes I contemplate how to go about this. Maybe start by offering data analysis services to charities. They usually need some numbers crunched for reporting and grants. I could run their numbers in exchange for recommendations and referrals. Seems like it might work. Perhaps I would offer data analysis to some small businesses and let them pay in trade (a month or two of gym membership in exchange for number crunching for a fitness center, for example).
Part of this whole elaborate fantasy has been trying to figure out what I would charge. Imagine it yourself. Do you charge by the hour or by the job? What is your time worth? Taxes? Benefits? What will the market support? I've hunted around for answers to all this. I'll save you the googling and sum up what I found. Start with what you would expect to be paid to do the job full-time for someone. Add in the cost of benefits, including retirement, and taxes. Now take that number and divide by 48 (weeks in a year) and by 40 (hours per week). You're not done yet. Consider that this type of consulting is usually a one shot deal. You need to factor in time to find new clients, advertising, administrative work. All that stuff that would be handled by other people at a consulting firm. Take the number you calculated and multiply it by 3 or 4 to account for all this other work you'll need to do. I came up with $125-150/hr. That number scares me. I'm used to grad student wages.
As for the by the hour or the job question: the consensus from consulting forums seems to be charge by the job. The reason for this is that you can't be certain how much time it may take you to do a job. Businesses often want the total cost (or at least max cost) up front. You trap yourself into a certain amount of hours and have to finish the job even if it takes more time than you thought - even if you have to work for free. Conversely, if you can do the job faster than people think it should take, you get a bonus. So now what do you do with your hourly rate? Time to come up with a menu and starting prices. Try doing some standard analyses and time how long it takes you. Add some buffer time and now you have a starting price. There will likely be negotiation. Be prepared for that. I've never negotiated myself, also terrifying.
And all that is before dealing with legal things, like going solely as self-employed or starting an LLC or something.
People can start consulting while in grad school. I'm currently unemployed. I have even more time I can put into this idea. It's just terrifying. But imagine if you could make it work, if you could make a career of it. Imagine making $5000-8000/month. Tempting, isn't it? How fast could you pay off your student loans with that? Own a house? Imagine how many shoes you could buy! Definitely tempting but so damn terrifying. I don't know if I'm ready for that. Could you do it?