This document clarifies what examiners are looking for when assessing the quality of evaluation in candidates answers.
Well worth a read!
http://filestore.aqa.org.uk/subjects/AQA-2140-W-TRB-OGEGT.PDF
And here’s a guide to what you should know:
AQA: http://www.aqa.org.uk/subjects/economics/as-and-a-level/economics-2140/subject-content
OCR: http://www.ocr.org.uk/qualifications/as-a-level-gce-economics-h061-h461/