This is a terrible game mechanic. Pay a pittance in gold and get a random free technology!
There's no strategy involved at all because the only downside to signing a RA is that the other Civ will also get a free tech, but that doesn't matter because the AI is just going to sign a RA with someone so it may as well be you.
Throw in the fact that RAs are better than 80% of the wonders in the game and well... IMO research agreements are the crown jewel of poor decisions by the civ5 team.
As long as there is another Civ with enough gold to enter an agreement the AI will sign one, they ignore pacts of secrecy etc.The AI does not always sign an RA with another Civ. How in the world is an RA better then 80% of the wonders?? Wonders get you happiness, culture, GP points, GA extensions, military bonuses, and several other bonuses. Try an RA plus wonders and you will florish!