World Expos held in six major economic regions

Economic Region	Host City	Time
Boston-New York-Washington	Philadelphia New York	1876, 1926 1939-40, 1964
Great Lakes	Chicago Montreal	1893, 1933 1966, 1967
Northwestern Europe	Paris   Brussels Amsterdam Seville Lisbon Hanover	1855, 1867, 1878, 1889, 1900, 1925, 1937 1935, 1958 1883 1992 1998 2000
Central and southern UK	London	1851, 1862, 1908
Tokaido	Osaka Tsukuba Aichi	1970 1985 2005
Yangtze River Delta	Shanghai	2010

From the delta to the world

Although the Shanghai World Expo can effectively improve the international status of the Yangtze River Delta city cluster, there are still many problems to be solved. Regional integration is the biggest problem facing the Yangtze River Delta, according to Liu.

In general, world-class economic regions often form a highly efficient coordination mechanism by means of regional planning and related legislation, or rely on joint consultation systems between city governments. For example, in 1964, London created the Greater London Council to take charge of area management and development. Subsequently, in 1985, according to the Local Government Act, the Ministry of the Environment undertook the responsibility for strategic planning.

Although there are similar joint consultation systems in the Yangtze River Delta, many administrative systems are still fragmented. For example, the problem of algae treatment in Taihu Lake continues to drag on due to administrative divisions between the cities along the lake.