The Globe and Mail reports in its Monday edition the list of Canadian stocks that typically pass the Ben Graham net-net working capital screen is not a long one. Guest columnist Robert Tattersall writes that as a deep value investor, he uses this screen for identifying attractive purchase candidates. However, the recent output challenges even the hardiest contrarian investor. To arrive at a net-net stock, take a company's current assets (primarily cash, accounts receivable and inventory) and deduct its current liabilities. This leaves you with net working capital. From this number, you deduct all other liabilities to derive net-net working capital. Companies with a market value below net-net working capital are essentially companies trading below liquidation value per share. The group average return for 2012 was 18 per cent, compared with 4 per cent for the S&P/TSX composite. The 2013 list includes ADF Group, Bri-Chem, Strategic Metals and Benev Capital. By Dec. 18, 2013, an equal-weighted portfolio made up of this group had delivered a year-to-date return of 2 per cent. This was below the 7.2-per-cent return from the S&P/TSX composite, but the two-year return is still ahead of this benchmark.