Sentence:  For the industry of this model , the effect of such public pressures in the past has been to hold the price well below the short-run profit maximizing price ( given the wage rate and the level of GNP ) , and even below the entry limited price ( but <WSD>not</WSD> below average cost ) . 
Meaning of the word marked with <WSD> tags:  negation of a word or group of words