@Goldencub is correct that you’ll have major issues.
Econ is an impacted major within L&S. Because of this, the administration imposes a deadline that requires you to meet all requirements by the end of your first semester at Berkeley.
See: https://www.econ.berkeley.edu/undergrad/prospective/transfer-students
It’s also not physically possible to pursue the economics major if If you don’t have Calc I complete by the end of Spring due to the course sequence of the prerequisites. The latest possible timeline to have a chance of meeting all the prerequisites:
Spring 2016: Calc I (Differential)
Summer 2016: Calc II (Integral), Intro to Microeconomics, Intro to Macroeconomics
Fall 2016: Intermediate Economics (either Micro or Macro), Applied Statistics, Submission of a Major Declaration Form
See: http://guide.berkeley.edu/courses/econ/
Additionally, Econ hopefuls also tend to overlook the logistics of impacted courses…
A lot of people try to backdoor into the major using the same strategy your counselor recommended. Because of this, combined with the vast majority of freshmen-admitted Haas hopefuls applying to Economics as their backup major, there is a huge bottle neck for some of the “core” prerequisites at Berkeley (Stats 20/21, Econ 100/101/A/B). Seats in these classes are at a premium and classes fill up even before the vast majority of transfers start registering. The current state of the campus is that Econ transfer pre-admits have to be saved spots in those said courses.
…basically if your not an econ pre-admit, then your chances of getting off the wait-lists and enrolling in both required courses are basically nil. It’s a huge gamble for non-econ admits as you essentially waste your Phase I to add classes you have close to no shot of getting into.
See: http://www.berkeleytime.com/enrollment/?course1=2018-fall-2015-52145&course2=2017-fall-2015-49705&course3=2019-fall-2015-51188&course4=2020-fall-2015-51128 (Look at the wait-list data!)
I’m sorry to hear you got bad advice from a counselor, but I recommend you stay an additional semester (or two) in community college to finish the prerequisites if you want to pursue Economics. A GPA of 3.86 is indeed in the competitive range to get into the major as a pre-admit with the requirements met.
On another note: [UCLA does not allow Non-Econ transfer admits to switch into Econ.](https://www.admission.ucla.edu/prospect/adm_tr/lsmajors/econ_pre.htm) Unfortunately, there is no back door into UCLA Economics.