PPE at Hertford College
Choice of school subjects isn't crucial for PPE. We welcome both A-Levels and comparable awards like the IB, as well as equivalents from other countries. Earlier qualifications (such as the GCSE) are important only for showing general commitment to work and competence in writing and Mathematics: a strong set of results (e.g. 7 top grades or more) will count in your favour, but weaker results won't ruin your chances.
Choice of School Subjects
Note that there is no expectation that you will have studied any of Philosophy, Politics or Economics at school. Taking one of them for A-Level – for example – shows enthusiasm for the subject (so it won't count against you), but will be of relatively little help in gaining admission. Far more important is the analytical and critical ability that you show in the test and especially the interviews. To develop these sorts of skills, traditional academic subjects (such as History, Languages, Religious Studies, and the Sciences) are likely to be best. But to prepare for Economics (and indeed for some of Philosophy), Mathematics is by far the most important skill, so if you're not already taking it, do seriously consider AS Mathematics in the upper sixth. You will need to use a fair amount of Maths in first year Economics, so learning as much as possible at school is much better than leaving it to be done at Oxford (when you will anyway find the workload much tougher than school). Another important point to bear in mind is that if you are marginal at interview, and our economists are unsure about your mathematical skills, it may tip the balance if they know that you are still taking Mathematics in the sixth form, and hence are likely to be better at it by the time you finish school, rather than even more rusty.
Do I Need Three "A"s (or Equivalent)?
The short answer is, standardly, "yes". Our admissions are so competitive that we have to turn away lots of very strong candidates who will get three "A"s (or equivalent), so we can only accept less in special circumstances. For this reason it can be an advantage to take four A-Levels so as to have a "backup". But we would not advise doing lots of A-Levels for their own sake: better to put your efforts into stretching yourself further with more demanding qualifications such as Advanced Extension Awards, the STEP papers in Mathematics, and/or by taking a musical instrument to a high grade. Don't do these to please us, though: do them for a far better reason, because they will benefit you! (And notice that – unlike some other places – we will never 'punish' you for doing more ambitious qualifications by setting you an admissions offer that requires you to do well in them: so if you do badly in STEP, for example, this won't affect your admission at all, since that will be based on the standard A-Level offer.)