I conducted an experiment, in which I measured participants altruism (and scored them from 1 to 5 according to their answers means) and let them indicate their willingness to pay for multiple products. Additionally I surveyed their gender, age, income and level of education. Using pearson correlations, i can tell that altruism indeed had an effect on the willingness to pay for certain products.
My question now, how do I check for effects of the socidemographics in this relationship between altruism and WTP?
My university's supervisor suggested to run linear regressions with the WTP as dependent variable and altruism and the sociodemographic variables as independent variables. But instead of simply plugging in the education variable (that has a value for each level of education) i should rather compute new dummy variables. For education for example that would be a dummy variable that has value 1 if the participant has a bachelor's degree and 0 otherwise, another variable that is 1 if the participant has a master's degree and 0 otherwise. I don't really get why I should do this for the regression. Wouldn't it make more sense to do t-tests in this case?
Maybe I completely misunderstood him but I do not understand why I should do it in this way. Maybe someone can clarify that for me.
Thanks!