英语单词讲解 unit 31
A market economy is an economy in which decisions regarding investment, production and distribution are based on supply and demand, and prices of goods and services are determined in a free price system utilizing voluntary exchange. The major defining characteristic of a market economy is that decisions on investment and the allocation of producer goods are mainly made through markets.
A mixed economy is an economic system in which both the private sector and state direct the economy, reflecting characteristics of both market economies and planned economies. Most mixed economies can be described as market economies with strong regulatory oversight and governmental provision of public goods. Some mixed economies also feature a variety of state-run enterprises.
Urbanization is a population shift from rural to urban areas, and the ways in which society adapts to the change. It predominantly results in the physical growth of urban areas, be it horizontal or vertical. Urbanization is relevant to a range of disciplines, including geography, sociology, economics, urban planning, and public health. The phenomenon has been closely linked to modernization, industrialization, and the sociological process of rationalization. Urbanization can be seen as a specific condition at a set time (e.g. the proportion of total population or area in cities or towns) or as an increase in that condition over time. So urbanization can be quantified either in terms of, say, the level of urban development relative to the overall population, or as the rate at which the urban proportion of the population is increasing.