Was a civil engineer moved to data analysis.
My role is mostly BI, reporting and such, but some cool stuff thrown in machine learning, predictive analytics, yada yada. Mostly learned on the job, but Excel in my engineering life was the gateway drug. I was able to demonstrate my interest and attitude to get foot in door. Engineering background is looked upon fondly, econ should be fine too.
I like the data stuff more than the CE stuff because I mostly get to chill on the computer, program a little, Excel a little, Tableau a little, surf stackoverflow a little without having to deal with too much corporate b.s., sales b.s., fudging numbers for a client b.s, writing long-winded technical reports about CE projects. I just geek around all day now, and explain it in human terms to the non-nerds. The future of data looks very good and very interesting with AI and such. Honestly could apply to any industry. Salary seems better than civil engineering, with less stress.
Would echo that agism shouldn't be a huge problem. Seems to be more of an issue in straight software dev, where you have 20 y/o Indians who will stay up all night and ruin their health competing against you. Data analysis is more nuanced, and actually requires some real life common sense, biz aptitude, and communication skill that the newbs suck at. And yes, there are 50 year old analysts who are quite skilled, more-than-decently compensated, and very content. 30 is nothing in data analytics field. At many companies you'd be the youngest there.
I agree just go for it. Start with becoming very good at Excel, then SQL, then either R/SAS/Python. Find a way to demo your skills or ability to think threw a problem. There is lots of free data out there to play with.