Explain why no modern nations have a purely free-market economy?

Pure market economies do not exist because when markets are allowed to freely function, and economic decisions are reached by the interaction of individuals, firms and goverment in the markets, these lead to sharply unequal outcomes and social welfare is threatened.

In turn, mixed market economies are established, where economic authorities implement income redistribution systems that reduce income inequalities and generate fairer outcomes for all the individuals that conform a society.

after the roman empire fell, some of its cultural achievements lasted for some time and others were lost. lost achievements include architecture , coins, and literacy. however, several things remained, such as the language. people may not have spoken this language in every city, but it influenced the languages they did speak. they also created the julian , which was commonly used until the eighteenth century.