Developed countries have market economies in which your livelihood is dependent on how others value and compensate you for the goods or services you provide. You're a slave to others. Wages in the west have been stagnant while cost of living has increased. More women entering the workforce has decreased/stagnanted wages. Alternatively, most people in developing countries live in subsistence economies (the west before industrialization as well) where your livelihood is dependent on whatever that person can cultivate, hunt/gather, or raise in terms of pastoralism.