[Matthyze]

The sentence as a whole is meaningful, which you can see by excluding 'to a combination of tariff and non-tariff':

> This calculation assumes that persistent trade deficits are due factors that prevent trade from balancing

The 'tariff and non-tariff' phrase is _technically_ superfluous but, subtextually, it implies there are such non-tariff reasons.

[namdnay]

A persistent imbalance is due to factors that prevent balance? And those factors can be of type T or not of type T? That’s slightly tautological :)