Japanese companies are once again predicting industrial production will keep picking up next month. But can you believe them? Looking at past predictions invites skepticism.

Each month, the government puts out a 70-odd-page industrial production report, with a survey on where firms think production will go in the next two months tacked on to the end. Economists rely on the survey for a broad picture of what's ahead, although the report is notoriously optimistic.

In the survey that came out with Wednesday's industrial production data for September, companies forecast production would rise 4.7% in October, then decrease 1.2% in November.

The data also showed production rose only 1.5% in September -- a far cry from the 5.2% predicted in last month's survey.

Since 2008, firms have forecast a figure on average 1.8 percentage point higher for the coming month than the actual number that came out. The actual figure has matched or beaten the forecasts only nine of 59 times.