The use of "conditional / hypothetical / not necessarily true" would have [been] rather than Simple Past were in OP's examples is a kind of linguistic "hedge".
Normally we think of hedges like this as "weakening / softening" the impact of an assertion, but it's not obvious that's the effect in the specific examples cited. The way I see it, the author is implying something along the lines of if you were to study this issue carefully, you would come to the conclusion that [whatever is being asserted in this sentence is true].
I think this leads to the further implication that the author himself has in fact studied the issue in depth, and come to the stated conclusion, so you should believe what he says - because he knows more than you, and is better qualified to exercise judgement, where irrefutable evidence is lacking.
In practice it's unlikely that the reader is going to conduct more research than the author, since this particular style of writing is often favoured by people who are experts in their field. So although we tend to say that hedging weakens an assertion, in certain contexts it actually adds authoritative emphasis. A bit like the way "understatement" often has the net effect of amplifying a point being made, rather than undermining it.
Some academics will doubtless imagine that by saying something would have happened rather than did happen, they're somehow "protecting" themselves from being proved "wrong" if further evidence comes to light showing that whatever they claimed happened could not have been true. Personally, I don't buy that perspective, but I'm sure it's often a significant factor in choice of phrasing. If they'd been honest, they'd have expressed the lack of certainty more explicitly (by saying something might have or probably happened, for example.