中文摘要
我们构建了一个李嘉图贸易模型，其中各国创新的思想在全球范围内扩散。我们的核心结果给出了创新与扩散产生最大稳定 Fréchet 生产率的充分必要条件，将广义极值支出与知识流动联系起来。创新使一国在技术上独树一帜，降低了其与其他国家的替代性。相反，扩散产生了技术相似性，加剧了面对面竞争与替代性。在一个各国不共享思想的仅含创新的模型中，各国生产率相互独立，且支出为 CES 形式。因此，对 CES 的偏离揭示了扩散模式。（JEL F11, O31, O33, O41）
Abstract
We develop a Ricardian model of trade where countries innovate ideas that diffuse globally. Our key result provides necessary and sufficient conditions for innovation and diffusion to generate max-stable Fréchet productivity, linking generalized extreme value expenditure to knowledge flows. Innovation makes a country technologically distinct, reducing its substitutability with other countries. In contrast, diffusion generates technological similarity, increasing head-to-head competition and substitutability. In an innovation-only model where countries do not share ideas, productivities are independent across countries and expenditure is CES. Consequently, departures from CES reveal diffusion patterns. (JEL F11, O31, O33, O41)