This is the smoothing machine, the pattern behind the reserve releases mentioned in the net income entry.
Recall how reserves work from the coffee shop: offices owe you $50,000 for supplied coffee, you estimate $5,000 will never be paid, and you book that $5,000 as an expense now, a cushion against future defaults. The estimate is a judgment call, and that is the door. In a great year, you estimate pessimistically: reserve $10,000 instead of $5,000. Profit takes an extra hit, but the year was great anyway, nobody minds. The surplus sits quietly on the balance sheet, cookies in a jar. Then a bad year comes, and you "reassess": customers look more reliable now, $3,000 suffices. The $7,000 excess flows back through the income statement as profit, cushioning the bad year. Reach into the jar when hungry.
The result across years: reported profits look eerily smooth, gently rising, no nasty surprises, while the real business bounced around underneath. Markets love smoothness and reward it with higher valuations, which is exactly why managers manufacture it. The trick applies to any estimated reserve: bad debts, warranty costs, restructuring charges, legal provisions, insurance losses.
Why it is genuinely dangerous rather than cosmetic: smoothness is information destruction. An investor cannot see how the business actually behaves in hard times, the one thing they most need to know. The SEC has repeatedly pursued extreme cases (it is the practice that got even General Electric in trouble), but mild versions are endemic and legal.
How a reader spots it: earnings implausibly steady in a volatile industry, reserves as a share of receivables or revenue swelling in good years and mysteriously shrinking in bad ones, and profit "beats" that land with suspicious precision quarter after quarter.