From 1990 to 2017, both per capita nominal country gross domestic product (PCGDP) and gross domestic product at purchasing power parity (PCGDP-PPP) follow, except for a few low-income countries, stretched exponential distributions (SED) $exp(-x^{\beta })$ as complementary cumulative distributions, with $0.5<\beta <0.7$ (fat tails) for PCGDP and with $\beta$ close to 1 (quasi-exponential behavior) for PCGDP-PPP. After 2008–2009 world financial and economic crisis, as $\beta$ approaches 1, PCGDP-PPP SED seems to converge in time to an exponential, in accordance to a simple econophysics analogy between conservation of energy in elastic collisions (Boltzmann–Gibbs distribution) and money in economic trade. As compared to nominal or market values of PCGDP, our results may reinforce the use of PCGDP-PPP as a more accurate and stable measurement of average economic activity across countries.

从1990年到2017年，人均名义国家国内生产总值（PCGDP）和按购买力平价计算的国内生产总值（PCGDP-PPP）紧随其后，除了少数低收入国家以外，其指数分布（SED）有所扩大 $经验值（-X^{\beta }）$ 作为互补的累积分布， $0。5<\beta <0。7$ （胖尾巴）用于PCGDP以及 $\beta$PCGDP-PPP接近1（准指数行为）。在2008-2009年世界金融和经济危机之后，$\beta$方法1，根据在弹性碰撞中的能量守恒（玻尔兹曼–吉布斯分布）与经济贸易中的货币之间的简单经济学物理学比喻，PCGDP-PPP SED似乎在时间上收敛为指数。与PCGDP的名义或市场价值相比，我们的结果可能会加强PCGDP-PPP的使用，作为对各国平均经济活动的更准确和稳定的衡量。