According to The Economist, on a purchasing-power-parity (PPP) basis, the Chinese economy became the world's largest in 2013.[16] On a foreign exchange rate basis, some estimates in 2020 and early 2021 said that China could overtake the U.S. in 2028,[17] or 2026 if the Chinese currency further strengthened.[18] As of July 2021, Bloomberg L.P. analysts estimated that China may either overtake the U.S. to become the world's biggest economy in the 2030s or never be able to reach such a goal.[4] Some scholars believe that China's rise has peaked and that an impending stagnation or decline may follow in the 2040s.[5][6][7]