Some of the advantages achieved through public opinion polling are the ability to better predict the outcome of elections, determine how the public's views change during a period of time and the gaining of a better understanding of the issues in question by those individuals who are being polled. An improved awareness of the issues at hand, which can be generated by polls, leads to active dialogues and more informed choices. The results obtained through polls also began to have an effect on the decisions made by political leaders during the 1980s as elected officials no longer needed to guess at what their constituents were thinking.
It has been argued by some observers that opinion polls can sometimes work to influence the choices made by voters in addition to just predicting their ballot selections. There are two theories regarding how this might occur: the bandwagon effect and underdog effect. The bandwagon effect is believed to act as a persuasive force that can cause some voters to switch their support to the candidate that the polls show is leading. The underdog effect is the inverse, and is believed to cause some individuals to vote out of sympathy for the candidate that the polls show is losing.