How will the economic world look in 40 years or so?

A new report from banking giant HSBC, entitled “The World in 2050”, takes aim at that question, and comes up with some intriguing answers. According to London’s Telegraph, the report — which is based largely on the theoretical work of Harvard professor Robert Barro — says the U.S. and China will be far ahead of the rest of the world, with Turkey, Egypt, Malaysia, and Indonesia all growing in influence and Japan, Russia, Germany, and Korea all losing ground.

“The bank said China would snatch the top slot as expected, but only narrowly,” the Telegraph reports. “China at $24.6 trillion (constant 2000 dollars) and the US at $22.3 trillion will together tower over the global economy in bipolar condominium — or simply the G2 — with India at $8.2 trillion far behind in third slot, and parts of Europe slithering into oblivion.”

A big part of the study’s findings involve national birth rates. “America’s high fertility rate (2.1) will allow it to keep adding manpower long after China’s workforce has begun to contract in 2020s and as even India starts to age in the 2040s,” the Telegraph says in dissecting the report. “The low fertility of Korea (1.1), Singapore (1.2) Germany (1.3), Poland (1.3), Italy (1.4), Spain (1.4) and Russia (1.4), more or less dooms these countries to aging crises and population decline unless they open the floodgates to immigration.” Japan’s already-shrinking population is part of the reason it hasn’t been able to recover from its “lost decade”, the Telegraph reports.

The study makes several big assumptions, including that the world will avoid an energy crisis and overcome the depletion of natural resources. Overall, it expects world growth to average 3% per year through 2050, with global economic output tripling over that period.