The Frankel-Wei regression framework measures the comovements between currencies, and assumes that all foreign exchange rates share a common numéraire. The International Monetary Fund's (IMF) Special Drawing Right (SDR) is a regular choice for the common numéraire. However, the five-currency basket of the SDR lacks diversification, which results in significant positive comovements between the basket currencies and the SDR currency basket. Consequently, the estimator of the regression coefficient is biased away from its true value. We suggest that the common numéraire be a large well-diversified currency basket, rather than a small undiversified currency basket, such as the five-currency SDR.

Frankel-Wei 回归框架衡量货币之间的联动性，并假设所有外汇汇率共享一个共同的数字。国际货币基金组织 (IMF) 的特别提款权 (SDR) 是普通货币的常规选择。但是，SDR 的五种货币篮子缺乏多元化，导致篮子货币与 SDR 货币篮子之间存在显着的正联动。因此，回归系数的估计量偏离了其真实值。我们建议普通货币是一个多元化的大型货币篮子，而不是一个小型的单一货币篮子，例如五种货币的特别提款权。