Because personal incomes and expenditures are so critical to the overall pace of economic activity, economists attempt to predict what the report will show before it is released. One way they do this is to go straight to the data sources. The largest source for monthly expenditures information is the Advance Monthly Sales for Retail and Food Services report. Spending on some retail goods, though, is more significant than that on others. Durable goods, as noted above, are more economically sensitive than nondurables. Among durable goods, some are better as predictors of macroeconomic conditions. Wall Streeters, for instance, watch the “RV indicator.” Recreational vehicles, or RVs, are usually purchased out of discretionary or unessential in....