Well, for starters, economics is no light subject. Is it a textbook you are reading? Some tips that I have gotten are that the most important information is in the first & last paragraph of a chapter, as well as in the first & last sentence of a paragraph. I have not taken economics but I am taking a statistics course, & I find that doing problems tends to help more than just reading about it. Also, I don't really understand the more abstract concepts like why something is the way it is, I just try to focus on what the outcome is & why that is important.

But I can assure you that you are not stupid. I'm in 3rd yr university & have the same types of problems, not always able to understand. Sometimes, certain subjects are written in a more dense, hard to understand style (like law). It takes longer to process. A lot of articles are written for academia or ppl w/very advanced knowledge on the subject...not for lay ppl. So, no, your not stupid...I'm pretty sure your issue is probably more common than you think.