The OECD has piloted a new economic model extrapolating from now to 2060. Their unsurprising conclusion is that poor countries will grow faster than rich countries; and that incomes between countries will tend to converge. The research dows reflect many of the assumptions laid down in the first years of this century. Globalisation, the rise of China and the Great Stagnation (whose first phase was called the Great Moderation due to the initial accumulation of debt) are all factored in.
The model takes no account of politics, disruption or revolution: the stresses and strains that all countries tend to buckle under as they journey through the unforeseen byways of modernity (being that which is always ahead of us). Think of what could destroy the expected growth: new energy sources (shales for one); demographic decline in China and Northern Eurasia (no people, no growth); the decline of melting pots and their incorporation into new cultural spheres (Unidos Estados de Americanos, a Sinicised Australia, an Africanised Europe, a Russian kalifaat). Perhaps a Singularity!