In 1990, the US accounted for 20.16% of the global economy, measured by purchasing power parity (PPP). That share peaked at 21.01% in 1999, with an economic output of $9.6 trillion, compared to a global output of $45.85 trillion.
However, the US portion has steadily declined since, with the sharpest drop occurring between 2006 and 2008, when it fell by 0.6% annually. The US share temporarily increased during Barack Obama’s second term, reaching 16.26% in 2014 and 2015, but failed in sustaining the momentum.
By the end of Obama's presidency, it fell to 16.04%. Subsequently, the US share declined by another 0.7% under Donald Trump. In Biden's second year, the US share slipped below 15%, reaching 14.82% by the end of 2023.
IMF estimates predict the trend will continue, with the US share falling by another 0.06% by the end of 2024, resulting in a cumulative decline of 0.58% under Biden to 14.76%.
Meanwhile, China’s share of the global economy has surged to 18.76%, while Japan's share has dropped by 4.33% over the past 33 years.