Hi Dr Physics, I know some Spanish Phd candidates. If they are lucky they earn about as much as a cashier in a supermarket say about 900€.
I coached one of these Phd candidates. She was already a year in and starting to crack under the psychological terror of her tutor (really psychological warfare tactics)
Anyway. When starting to look at her motivations and goals we started exploring. She said her goal was to become a university professor. OK, as a coach you get to ask the stupid questions "What would it take to become a university professor?" "..."
She did not know, so she went to find out:
After completing her doctorate (in about 4 years, obviously she had a Bachelor's and Masters already so 4 years already done)
After 8 years of study she would have a Phd in her hands. Not enough...
She found out it "is expected" that she'd do a Post-doc of another year of course abroad
... still not enough
After that she might be accepted as an Assistant professor, which would mean that she'd need to do the dirty work for about 600€ a month and thennnn...if she did not step on anyone's toes ... she might be accepted as a full time professor.
And will make about 2000-2500 € a month.
So that is an investment of
Bachelor 3
Masters 1
Phd 4- 6 (many seem to plateau and stick around before finishing)
Post doc 1
Assistant Professor 2-4
So in total about 11 - 15 years of your life to get a job with a pay any normal professional should be earning in the first 5 years of their career.
Needless to say, she started to realize she was wasting her time and found a job teaching in high school which was something she enjoyed much more...