It looks like you threw out the people who gave 0 to charity when you took the log. I typically use ln(x+1) for these types of variables, which maps zero to zero.
In this case, your approach leads to stronger effects (or at least lower p values). Repeating your analysis with the full data set (n=575), it’s actually statistically significant on its own (Welch t=2.03, p=.043), means of 5.25 vs. 4.92. Excluding non-givers also gives lower p-values in the analyses I described here; when controlling just for age the effect of consequentialism is significant at p=.001 (geometric means $204 vs. $121). Even though the trend is for consequentialists to be more likely to give than non-consequentialists, it looks like the added noise of having all those points at zero has a bigger effect.
I threw out zero because it seems like a non-response to me in a lot of questions. Someone giving a number shows they have at least responded with a non-default and did donate something, while someone leaving a zero may be simply equivalent to people who left empty responses.
(While I’m commenting on my analysis: from a utilitarian perspective, comparing logs doesn’t even make sense; personal utility may follow some sort of logarithm in money, but charities don’t—the problems are just too big for any one person.)
Logging the total charity donations:
It looks like you threw out the people who gave 0 to charity when you took the log. I typically use ln(x+1) for these types of variables, which maps zero to zero.
In this case, your approach leads to stronger effects (or at least lower p values). Repeating your analysis with the full data set (n=575), it’s actually statistically significant on its own (Welch t=2.03, p=.043), means of 5.25 vs. 4.92. Excluding non-givers also gives lower p-values in the analyses I described here; when controlling just for age the effect of consequentialism is significant at p=.001 (geometric means $204 vs. $121). Even though the trend is for consequentialists to be more likely to give than non-consequentialists, it looks like the added noise of having all those points at zero has a bigger effect.
I threw out zero because it seems like a non-response to me in a lot of questions. Someone giving a number shows they have at least responded with a non-default and did donate something, while someone leaving a zero may be simply equivalent to people who left empty responses.
(While I’m commenting on my analysis: from a utilitarian perspective, comparing logs doesn’t even make sense; personal utility may follow some sort of logarithm in money, but charities don’t—the problems are just too big for any one person.)