I do not read The Economist so I cannot give my opinion on that magazine. However, I do read Time and feel it would be a very good magazine for learning English. The articles are well written and cover a wide range of topics. Good luck.

I'm going to subscribe to "The Time" or " the Economist." I would appreciate it if you adviced me which one.

I'm honestly not too familiar with the Economist. Time magazine however has a wider range of topics, and strives to be very up-to-date by covering recent events. Therefore I'd suggest Time magazine. If you are looking to improve your English reading comprehension and/or have the vocabulary to use in order to hold conversations on current topics you might also try Time online or the Huffington Post. By the way you want to use "advised" instead of advice in your original question.