But some of those companies have started to offer more detail than ever on how much shrink, or items lost to factors like external or employee theft, damage or vendor fraud, is cutting into their bottom lines.

At the same time, certain retailers pulled back on their contention that organized theft is a primary cause of losses, as scrutiny grows over claims about how much crime contributes to their struggles.

During second-quarter earnings reports in August and September, nearly two dozen retailers said shrink has continued to weigh on profits. But the details each company provided, and the explanations they gave for losses, varied widely.

Many of them said that shrink is at an all-time high and said the industry is struggling to control it. Still, it's difficult to compare the losses to past years because most of the companies have never previously disclosed how much shrink cost them.

Generally, the inventory losses are only a small fraction of the retailers' net sales. They also pale in comparison to other factors squeezing margins, such as excessive discounting and promotions, according to a CNBC analysis of their balance sheets. While shrink is growing for some companies, losses are generally in line with the retail industry standard of 1% to 1.5% of sales — signaling the problem may not be as dire as certain retailers and trade associations have suggested.

When they reported second-quarter results, some companies like Target and Dick's Sporting Goods offered clues into how much shrink is costing them and squarely blamed theft. Target lost about $219.5 million to shrink during the three months ended July 29, while Dick's lost about $27.1 million during the same period, according to a CNBC analysis.