I am taking AP Econ this year and I wanted to get a review book for studying, but not for the AP test in May. I was wondering if the content in the 5ST5 AP Econ book 2009 differs greatly from today’s class. I was going to purchase a new one now, but I cannot decide between the most up to date 5ST5 or Barron’s. My brother got double 4s using the 2009 5ST5 book.