I had a colleague who inquired if I would be willing to do some data analysis on a project of his. I thought, sure, why not and had the disclaimer that if the project is viable I'm on.
He's a sweet fellow when the conversation is about the weather, sports, or the work schedule at a cocktail. As a person he can be kind of caustic and says stuff off the record that makes me cringe and want to wash my hands. He wants me to do a quantitative analyses of research output over a specific topic and categorize authors. He is trying to look for factors that he thinks contributes to "high quality research output and citations". He wants to group authors by race and the way he is assessing race is conjecture off of name, which I find honestly kind of stupid and a little horrific for this to be in academia. For example, we have a colleague of African descent, and on paper you could not tell him apart based on name alone from someone of European descent due to his combination of first and last name. He also specifically wants to compare the United States against countries from a specific region of the world he has had an off the record vendetta against, which he has made insensitive jokes about in the past. This is an individual that has been reprimanded once by the way by our institution but it was more of a slap on the wrist for name calling in an e-mail.
I don't want to put my hands on this project, because hypothesis and everything aside, I don't believe in it. I also am not interested in this kind of work anyway as I thought he was going to have data about an experiment in our field, not about researchers in our field. How do I tell him no after I opened the door at the beginning to be willing to collaborate? He e-mailed me data files, etc. CC'd on e-mails.