Income wise, which job is more profitable today, blue-collar or white-collar?

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In the early 1900s, there are more people who were engaged in blue-collar jobs than those who were engaged in white-collar. The percentage is something like 80% to 20%. These days however, white-collar jobs have increased to almost 50%. Does this suggest that white-collar jobs are more profitable? In your assessment, do you think the increase in white-collar workers means higher income? What possible implications do this shift suggests for you?