At least once a weekend, I'll hear a parent or a coach say "that was a make-up call!" Essentially, they are saying that because they didn't agree with a call, they are insinuating that I made a call to "make-up" for another call that went for their team earlier in the game. Is there any truth to this?
Not for me. Sometimes, one team winds up getting 75 or 80% of the fouls called in the game in their favor. It's not my fault that one team had more possession or that they know how to challenge for the ball without fouling their opponent. That's just the way it goes.
If I know that if a team is feeling particularly aggrieved in a game, I will be extra careful to watch up for fouls going both ways, but I won't create a call out of nothing. I don't blow my whistle to make anyone feel better. I can only call what I see.
There is research that does suggest a bias. A German study looking at 12,902 Bundesliga matches, noted that referee's were less likely to award 2 PK's to one team in a game. Additionally, that they are also more likely to award a PK for the other team later in the game than if no PK's had been called at all.
I will admit, in a few games, after calling a PK for one team, my bar for a PK may go up a bit later in the game for the same team. It's happened to me. I want to be absolutely sure of my call. No ref wants to decide the outcome of a match.
So, is there such a thing as "Make-up calls?" Consciously, no. But subconsciously, there may be some truth to it.