Optimal fiscal policy requires that tax rates be smooth over time, responding only to permanent changes in government spending.
最优财政政策要求税率随时间平稳变化，仅对政府支出的永久性变化作出反应。
那些说话算话的人有一点很天真：他们以为别人也和他们一样。
Sustainability is not just a trend, it's a responsibility we owe to the next generation.
创新是在竞争激烈的世界中保持领先的关键。