if compared between international students,a ps diploma(not in every case,and mostly depends on the field you studied,i.e if your field related jobs are more demanded u will be paid high)holder with a year experience earns more than a pg diploma holder.
dont ask me for links ,please...
its just common sense that a ps diploma holder who haves a 1year canadian work experince(basically 3 work terms) have a good chance of getting job and little high salary
**********all are some of my views and what i have seen in some colleagues experinces