The answer differs depending on political and economic thought. Austrian economist would point out Nobel prize winner Frederick Hayek's work The Road to Serfdom. The main reason is the threat of force from others. In exchange for some security people take on the oppression of the lord.
The Ludwig von Mises Institute has many free articles on the subject of economics and the relationship it has with economics.
Businesses are the most significant institution in the economic structure.
An economic institution is the set of norms relating to production and distribution of goods and services
Corporations
yourmom
Sharecropping
Serfdom was an unsustainable economic system, and it stunted the growth of the eastern European economy because eastern Europe maintained a farm-based economy long after the rest of the world had turned to an industrial economy.
Tsar Alexander II issued the "Emancipation Edict" which abolished the institution of serfdom.
Businesses are the most significant institution in the economic structure.
An economic institution is the set of norms relating to production and distribution of goods and services
The Road to Serfdom
social institution includes religion,family,politics, and economic.
socialism
Corporations
yourmom
Spain abolished serfdom in 1837
In western europe serfdom had largely disappeared and in eastern europe serfdom was firmly rooted
The Road to Serfdom was created in 1944-03.