Getting an interview with NERA and other economic consulting firms

I go to a nontarget liberal arts school in Massachusetts. I'm expecting to graduate this May with a BA in economics, while also minoring in Business Administration. I have had two main international internship experiences in China (one in finance/accounting, the other in international affairs) and have had a steady workstudy job in the IT field for 2+ years.

I want to break into the economic consulting field (as I feel I have a stronger chance within this field than breaking into the management consulting field given my economics background). I have a 3.9 cumulative GPA and a 4.0 major GPA.

My school has no recruiting whatsoever and I've been networking/applying to all sorts of jobs since last September - no luck. Unfortunately, much of the alumni from my college are not in the consulting field.

How can I land an interview with NERA and other economic consulting firms? Would it be possible to physically stop by the NERA office in Boston and hand drop my resume off? Or should I simply just apply online? I am just afraid that my application will get lost among the thousands of other applicants from better known target schools.

Also, is this a good time to apply? Not that I would stop this job search process, but do you think my chances of breaking into this field would rise right after graduation (because I would be available immediately for hire rather than reserving a spot for 5 months)?

Thanks