By global CAPM,domestic and foreign asset cost decided in same ways.the key is beta relative to global portfolio and this portfolio's market risk premium relative to risk-free rate.按照全球资本资产定价模型，国内和国外资产的资本成本以相同的方式决定。关键是相对全球市场组合的贝塔和该相同组合相对于无风险利率的市场风险溢价。
this is true from the visual.consider P&G and Unilever.both sell house-hold product globally,and mostly in same region.stock traded in american and europe.the main difference is P&G IS IN america,and Unilever is in UK and Dutch.similar business type and investor background,this wil be strange.in general,we find that comparable company's location do not influence their valuation level.for instance,american and euro medical company's valuation both in 12times of EV/EBITA,narrow space,whatever location.这从直观上也成立。设想消费品公司宝洁和联合利华。两家都在全球销售家庭护理产品，并大致地域相同。两家的股票在美国和欧洲交易。主要的差异是宝洁所在地是美国，而联合利华所在地为英国和荷兰。在这样类似的业务类型和投资者背景下，如果两家公司有不同的资本成本，这会很奇怪。总之，我们发现可比公司的所在地不会影响他们的估值水平。譬如，美国和欧洲医药公司的估值倍数都在一个12倍企业价值/EBITA（息税摊销前盈利）的狭小区间，无论公司所在地。
Technically, the GLOBAL capital Asset Pricing model only exists as long as PPP exists, which is true in the long run.
Although evidence for PPP has been mixed in the past, more recent academic studies have found that, on average, PPP differences between currencies reduce by half their value over three to five years.
In other words, exchange rates eventually adjust for inflation differentials between countries, though not immediately and completely.技术上，全球资本资产定价模型只在购买力平价存在时存在，这在长期属实。尽管购买力平价的证据在过去被混淆，更多的近期学术研究发现平均看，在货币间的PPP（Purchasing Power Parity，购买力平价）差异在三到五年间减少到他们价值的一半。换句话说，汇率最终在国家间对通胀差异做出调整，尽管不是立即和完全的。