Which is harder TSA or HAT

Which would be harder TSA (PPE) or HAT (History and politics) ?

I've done one of those exams and helped people prepare for the other - and I couldn't tell you which is "harder".

They're different exams testing different things.

It's like answering, what's harder, playing the piano or playing badminton? What is harder for you depends on your skill set and experience.

In any case, if one of the exams is easier, it is easier for every applicant - and your place will be determined based on how you perform relative to others.

If you're thinking that you might choose between PPE and HisPol based on how easy the application is, think again - choose the subject you like most and then work hard for whatever admission test it sets.