Deficiency deduction for associations limits set off of member contributions against income and bars carry forward. Provision applies to trade, professional or similar associations whose income is not distributed to members. General receipts from members and general expenditure for protection or advancement of members' interests are matched to yield a deficiency or surplus. A deficiency is allowable as a deduction against income from business or profession and, if remaining, against other heads in the same year after other deductions and brought forward losses; set off is subject to a statutory proportionate limit of total income. Unabsorbed deficiency cannot be carried forward.