Public responses to literary works have very often resulted in widespread sociopolitical and economic shifts. Recent examples include books written in Middle Eastern countries, where authors are very often persecuted for their beliefs and therefore struggle to change the status quo through their authorship. However, beyond specific examples, the semiotic theory as posited by Ferdinand de Saussere necessitates that a relationship exists between words spoken and real-world phenomena, otherwise known as "signs and "signifiers." For example, if an author were to state, "Apples are bad," the reader may then be influenced to avoid apples as a result of the relationship between the "signifier" that "signifies" a specific idea that is comprehensible to the reader ("sign"). This dyadic mode of thought is the basis of structuralism.
In postmodern theory, the relationship between literature and the "real world" is a little more complex. For the postmodernist, a "signifier" can actually be completely arbitrary and therefore subject to a variety of different interpretations. For example, if an apple-loving postmodernist were confronted with the sentence "Apples are bad," then this individual would not be as likely to accept the sentence at face value due to his/her preexisting cognitive bias. Furthermore, this sentence would be irrelevant were it posited to a postmodernist who had never even heard of an apple, therefore signifying the relative and highly specific relationship between reader and text. So clearly, literature does have an effect on the reader due to the comprehensible nature of "signs" and "signifiers," but the degree to which readers are affected by these semiotics depends entirely on context.