Sentence:  The threat of <WSD>effective</WSD> anti-trust action , provoked by `` gouging the public '' through price increases not justified by cost increases , and fears of endangering relations with customers , Congress , the general public and the press , all operate to keep price increases in some relation to cost increases . 
Meaning of the word marked with <WSD> tags:  producing or capable of producing an intended result or having a striking effect