Reasons of 'Justified' Inequality

Not all differences in economic outcomes represent unjustified inequality. Differences do not necessarily imply inequality. 
* Working more hours
* More unpleasant work
* Working harder; more work per hour done
* Level of responsibility
* Uncertainty of income (extensive margin)
* Fluctuations of income (intensive margin)
* Skill level (talent?)
* Amount of education/training/preparation (human capital?) required or going into one's workEven if a certain skill level is not required, it might have higher productivity, and possibly should still be compensated as such. (see Book: Inequality (Atkinson) 25-28: not all differences in outcomes are inequality)
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