Commodity Prices and P-Star
研究了Hallman等人提出的P-Star通胀预测指标，发现该模型仅利用M2与实际产出关系，忽略商品价格等变量，却在1970-1980年代优于其他预测方法。
A recent article by Hallman, Porter, and Small (1991), henceforth referred to as HPS, presented the P-Star (P*) indicator of future inflation. The HPS models exploit the stability of two long-run relationships: that between M2 and nominal output, and that between actual and potential real output. Despite paying no attention to other possible influences on inflation, such as commodity prices or interest rates, the HPS models produced better forecasts of the GNP implicit price deflator over the 1970s and 1980s than did a number of alternatives, including both univariate ARIMA models and the published forecasts of several econometric consulting firms.