Gary Liu

Executive director of CEIBS Lujiazui Institute of International Finance

China's GDP to overtake that of the US: 2030s

Double US GDP: Maybe never

By 2030: Economy will have run into serious difficulties without market reform and tackling environmental problems. US growth could pick up to 4 percent, making it almost impossible for China to be double the US size.

Duncan Innes-Ker

Senior China researcher, Economics Intelligence Unit

China's GDP to overtake that of the US: 2023

Double US GDP: Not forecastable but beyond 2030.

By 2030: China's GDP to be 30 percent larger than the US. Parts of Shanghai and the Yangzte River Delta will begin to look like developed nations such as Japan.

Xu Bin

Professor of economics and finance at CEIBS

China's GDP to overtake that of the US: 2018

Double US GDP: Any such forecast has too wide a margin of error

By 2030: Growth no longer guaranteed and could slip to low single digits without reform of state-owned enterprises.

Martyn Davies

Chief executive of Frontier Advisory, the research and strategic advisory firm based in Johannesburg

China's GDP to overtake that of the US: 2020

Double US GDP: Too optimistic. Underestimates the US' ability to reinvent itself.

By 2030: Almost unrecognizable from today with changes being as substantial as those since the 1990s. Reformed SOE sector and thriving private sector.

Miranda Carr

Head of China research at London-based investment research firm NSBO

China's GDP to overtake that of the US: 2025 to 2030

Double US GDP: 2050

By 2030: Already the world's biggest economy and a visibly more urbanized country with families and not just migrant workers moving to cities, which will require reforms to the household registration system and land reform.

Goolam Ballim

Group Chief Economist, Standard Bank Group, based in Johannesburg

China's GDP to overtake that of the US: 2020 to 2025

Double US GDP: 2030-2040

By 2030: China will find it easier to become double the size of the US than just catch up. Its output of scientists, engineers and accountants will reduce global wage rates for professional labor.

Qinwei Wang

China economist, Capital Economics, London

China's GDP to overtake that of the US: 2020

Double US GDP: Too many uncertainties. 2030 is on the optimistic side.

By 2030: China's growth is more likely to have proved boon for Western economies since consumers will be buying more high-end goods. This is in contrast to the first stage of growth when Africa and Latin America benefited from demand for iron ore, copper and other commodities.

George Magnus

Senior independent economic adviser, UBS, London

China's GDP to overtake that of the US: 2018 or 2019

Double US GDP: 2025-30, if current growth rates extrapolated but very optimistic.

By 2030: Government will have to have tackled debt to avoid a "Minsky moment" where there is some form of investment bust. China's per capita income likely to have trebled from now to between $15,000 and $18,000.

(China Daily 05/03/2013 page5)