This study suggests that women are more likely to reward with sex than men. This makes sense because women know exactly what will make a man feel deprived. A man is more likely to reward a woman with romance and attention, since that is typically what women covet.
The one point of the study I disagree with is how 78 percent of respondents didn't think there was anything wrong with using sex as a reward. I believe those who said so are unaware of the long-term consequences of having to "work" for something that should be freely given without strings attached.
In my experience of talking to audiences around the world, I have not yet run into anyone who says they don't mind having sex dangled as a carrot for good behavior. Sure, a man is interested in sex. When it is offered in connection with an expectation, however, it doesn't feel right. Yes, he will likely perform to get the reward (sex), but how do you think he is feeling toward you? If you're attempting to control him through a sex reward, he isn't feeling particularly loving toward you.