For thousands of years, cities have

For thousands of years, cities have offered higher average standards of living
than those available in surrounding rural areas. Economic historians estimate that the average income of city dwellers ranged from 1.5 to 3 times that of their rural counterparts at least until the Industrial Revolution changed the socioeconomic structure of Western Europe.14 Even today, average urban incomes are roughly three times those of their rural counterparts in both China and India. These income gaps reflect the capacity of cities to attract skilled workers and productive businesses and economies of scale that enable workers in cities to be more productive and reduce the costs of supplying basic services.15 McKinsey research in India suggests that it can be 30 to 50 percent less expensive for large cities
to deliver basic services including water, housing, and education than it is in
more sparsely populated rural areas. International airports, for instance, are economically viable only when they serve large urban centers. An estimated
$5 million of capital expenditure per daily flight is necessary in a city of five million people, compared with nearly $13 million in a city whose population is less than one million. But cost is not the only issue. Ensuring the necessary quality of services such as education can be more difficult in a rural setting. In India, rural school teacher absentee rates have run at nearly 25 percent.16
Cities attract people with the skills needed to power growth. The average education level of urban dwellers is higher than the level among those living in rural areas. In India, we see higher educational attainment increasing five times as fast in urban households as in rural households. In China, more than one-quarter of Shanghai’s population holds a college degree. Not only does the city produce more than 100,000 home-grown graduates a year, but it also pulls in talent from the rest of the nation and from overseas. The city’s expatriate population numbers half a million.
All these factors account for the fact that the world’s cities already make an overwhelming contribution to the global economy. Large cities are home to
38 percent of the world’s population but generate 72 percent of global GDP.17 However, urbanization is happening at very different speeds in different regions— partly because they are in different phases of the process. The United States
and Europe made the rural-to-urban transition long ago. Latin America, too, is in
a relatively mature phase of its urban journey. China is right in the middle of its sweeping urbanization, while India is in the early stages of the process (see Box 1, “The maturity of urbanization varies from region to region”).

14 See, for example, Ian Morris, Social development, October 2010 (www.ianmorris.org/socdev. html); Angus Maddison, Monitoring the World Economy 1820–1992, 1995; and Walter Scheidel and Steven J. Friesen, “The size of the economy and the distribution of income in the Roman Empire,” Version 2.0, Journal of Roman Studies, Vol. 99, January 2009.
15 There is a large body of literature on urban economics focused on assessing the nature
and size of urban economies of scale. See, for example, Edward L. Glaeser and Joshua D. Gottlieb, The wealth of cities: Agglomeration economies and spatial equilibrium in the United States, NBER Working Paper No. 14806, March 2009; World Bank, World development report 2009: Reshaping economic geography; and Indermit S. Gill and Chor-Ching Goh, “Scale economies and cities,” World Bank Research Observer, Vol. 25, No. 2, 2010.
16 M. Kremer et al. “Teacher absence in India: A snapshot,” Journal of the European Economic Association, Vol. 3, No. 2–3, April May 2005.
17 We define cities as broader metropolitan areas that include both
a core city and surrounding metropolitan regions integrated into a connected urban region. Large cities include metropolitan areas with 150,000 or more inhabitants in developed regions and 200,000 or more inhabitants in developing regions.

ผลลัพธ์ (ไทย) 3:

For thousands of years, cities have offered higher average standards of living
than those available in surrounding rural areas. Economic historians estimate that the average income of city dwellers ranged from 1.5 to 3 times that of their rural counterparts at least until the Industrial Revolution changed the socioeconomic structure of Western Europe.14 Even today, average urban incomes are roughly three times those of their rural counterparts in both China and India. These income gaps reflect the capacity of cities to attract skilled workers and productive businesses and economies of scale that enable workers in cities to be more productive and reduce the costs of supplying basic services.15 ด้านการวิจัยในอินเดียแสดงให้เห็นว่ามันสามารถ 30 ถึง 50 เปอร์เซ็นต์ที่แพงน้อยกว่าเมืองใหญ่
ส่งมอบบริการพื้นฐานรวมทั้ง น้ำ ที่อยู่อาศัย และการศึกษา มากกว่าจะกระจัดกระจาย
มากกว่าชนบท ท่าอากาศยาน นานาชาติ ตัวอย่าง มีศักยภาพทางเศรษฐกิจเฉพาะเมื่อพวกเขาให้บริการศูนย์เมืองใหญ่ ประมาณ
$5 million of capital expenditure per daily flight is necessary in a city of five million people, compared with nearly $13 million in a city whose population is less than one million. But cost is not the only issue. Ensuring the necessary quality of services such as education can be more difficult in a rural setting. In India, rural school teacher absentee rates have run at nearly 25 percent.16
Cities attract people with the skills needed to power growth. The average education level of urban dwellers is higher than the level among those living in rural areas. In India, we see higher educational attainment increasing five times as fast in urban households as in rural households. In China, more than one-quarter of Shanghai’s population holds a college degree. Not only does the city produce more than 100,000 home-grown graduates a year, but it also pulls in talent from the rest of the nation and from overseas. The city’s expatriate population numbers half a million.
All these factors account for the fact that the world’s cities already make an overwhelming contribution to the global economy. Large cities are home to
38 เปอร์เซ็นต์ของประชากรโลก แต่สร้างร้อยละ 72 ของโลก gdp.17 อย่างไรก็ตาม ความไม่แน่นอนเกิดขึ้นที่ความเร็วแตกต่างกันมากในภูมิภาคที่ต่างกัน ส่วนหนึ่งเป็นเพราะพวกเขาอยู่ในขั้นตอนต่างๆของกระบวนการ สหรัฐอเมริกา
และยุโรปทำในชนบทในเมืองเปลี่ยนไปนานแล้ว ละตินอเมริกาก็มี
ที่ค่อนข้างเป็นผู้ใหญ่ระยะของการเดินทาง เมืองของ