Every parade needs an audience. Although I'm detecting little fanfare for the fourth-quarter earnings parade that's set to begin after the close on Tuesday with aluminum giant Alcoa (AA), Foolish investors will line the streets to extract as much insight into the state of the global economy and the industrial outlook for 2013 as they can.

All signs point to another modestly profitable quarter for Alcoa as the company continues to make the most of an extremely challenging market environment for aluminum. Analysts are looking for earnings of $0.06 per share, a slight downward revision from prior projections for $0.07 per share. I discussed in some detail the key areas to watch for Alcoa in this premium research report available from The Motley Fool, and I encourage investors to gauge the company's performance over each the next several quarters using those company-tailored metrics.

Essentially, Alcoa's capacity to deliver shareholder value within this weak price environment for aluminum hinges upon its ability to sustain recent cost and productivity enhancements -- particularly within the company's alumina and primary aluminum units -- while continuing to reduce total debt. Particularly in light of Moody's announcement last month that Alcoa is under review for a potential downgrade of its debt, both the rate of debt reduction and the company's margin performance across all business units will come under the microscope this quarter.

For most investors, meanwhile, Alcoa's earnings reports provide a valuable update on the state of global industrial demand and the related forward outlook. In particular, the company provides a terrific window into the automotive and aerospace industries at a time when both of those industries have provided noteworthy oases of strength within an otherwise struggling global economy. For early hints regarding the business outlook for airliner manufacturer Boeing (BA -0.24%) -- or automakers like Ford (F 0.66%) and Tesla Motors (TSLA -1.92%) that are leaning on aluminum to yield lighter, more fuel-efficient vehicles -- Alcoa's quarterly assessments of these end markets are simply indispensable.

The report will also offer timely indications of industrial activity in China, which suffered significant setbacks during 2012 that were felt throughout the global economy. In this forthcoming release from Alcoa, I'll be looking for some confirmation of miner Rio Tinto's (RIO 0.43%) assertion that the worst of China's recent slowdown may already be behind us.