They are the % of votes in a country cast for its green party and its leftwing party. Joao, could you perhaps elaborate on the suggestion that the large coefficients may be due to predictions that are essentially 0 or 1? What does that mean exactly? For example, two regressors with very high coefficients are the leftvotes and greenvotes variables. Is it accurate? If so, do I understand correctly that the z value is another measure of significance, the value being below -2 or above 2 meaning that the regressor is significant? And is what you're saying effectively that the variables that are problematic appear to have no explanatory power anyway so the z values should 'wash them out' out the target, more parsimonious model? I have found this explanation of the z values in logistic regression: Nick, thank you for drawing my attention to the z values. So they do not change between the years, but the coefficients are normal in all years except 2007. Moreover, these variables happen to be time-invariant. In the earliest year (2007) the IVs with the large coefficients are factor variables, which excludes the possibility of it being down to different magnitudes.
However, I would like to ask some questions on the large coefficients. Okay, thank you Maarten for the link - having read up on the constant, it appears that it shouldn't be meaningful in this case, as 0 is not a meaningful value for all the regressors and most are factor variables.