engineering.
you can be an engineer and read books or take part-time courses to
learn economics. also it is about real life.. so it is not too
difficult.
you cannot do an econs degree and read books on engineering to
know/practice engineering.
engineering is more specialised...
engineering also makes more money for a start but at the rate
technology changes, you may become redundant after some years if
you do not upgrade yourself or if what you learnt is
out-dated/taken over by some other innovative technology making
yours redundant.
econs in this way is a sure-win.... the theories will always be the
same. alot more variety of options are also option for you...
banking, stockbroking, investments, etc.
ultimately depends what you want in life.