Public opinion is the aggregate pattern of views, attitudes, beliefs, preferences and judgements held by members of a population about political, social, economic or public issues. It is not simply a single opinion shared by everyone and it does not necessarily mean that a population has a settled or coherent collective position. Public opinion can concern support for governments or parties, views about policies, perceptions of institutions, evaluations of leaders, attitudes towards social issues or reactions to events. Political scientists commonly study public opinion because democratic governments operate within populations whose preferences and attitudes can affect elections, political agendas, policymaking and legitimacy.
Public opinion is an aggregate concept, meaning that it describes patterns across individuals rather than a literal mind possessed by society as a whole. A population may contain substantial disagreement, uncertainty and indifference, so describing public opinion requires specifying the population, question and time period. For example, public opinion among all adults can differ from opinion among registered voters, likely voters, party members or residents of a particular region. Opinion can also change after major events, changes in economic conditions, political campaigns or new information. Consequently, a statement that public opinion supports or opposes something is incomplete unless the relevant population, measurement question and period are identified.
Public opinion includes both policy preferences and broader political attitudes. Policy preferences concern issues such as taxation, healthcare, education, immigration or environmental regulation. Evaluative attitudes concern whether people approve of a government, trust an institution or believe a political leader is performing well. Political knowledge and factual beliefs can also form part of public opinion, although attitudes, beliefs and preferences are conceptually distinct. A person may support a policy because of a particular factual belief, while another person may support the same policy for different reasons. Measurement instruments therefore need to distinguish the object of opinion from the reasons, information and emotions associated with it.
Public opinion can be stable in some areas and volatile in others. Long established attitudes may change gradually, while opinions about newly emerging issues can move rapidly as people receive information and form judgements. Major events can temporarily alter responses, particularly when people are reacting to breaking news or dramatic circumstances. Polling researchers therefore pay attention to fieldwork dates as well as results. A poll conducted immediately after an important event measures attitudes at that particular moment and may not represent the longer term distribution of opinion. Repeated surveys using comparable methods are more useful for identifying sustained changes over time.
Public opinion is influenced by many sources of information and social interaction. Political parties, governments, news organisations, social media, family members, colleagues, community organisations and personal experiences can all contribute to the formation of attitudes. The relationship between public opinion and political communication is not necessarily one directional. Politicians can respond to existing public preferences, but campaigns and government decisions can also influence how citizens understand issues. Political scientists consequently study both the determinants of opinion and its consequences. A measured opinion is therefore a snapshot of attitudes within a particular informational and institutional environment rather than an independent variable completely detached from political communication.
Public opinion should be distinguished from public mood, public interest and public behaviour. Public mood is a broader description of how people feel about the political environment, while public interest refers to the topics receiving attention or considered important. Public behaviour includes observable actions such as voting, protesting, donating or contacting representatives. A person can hold a political opinion without acting on it, and behaviour can be influenced by factors other than opinion. Similarly, people can report an opinion about an issue without possessing extensive factual knowledge about it. Measurement therefore requires careful separation of attitudes, knowledge, preferences and behaviour.
Public opinion has a democratic significance because elected representatives operate within societies containing multiple and sometimes conflicting preferences. Opinion can influence electoral competition, party platforms, legislative agendas and government communication. At the same time, democratic institutions do not necessarily translate every measured majority preference directly into policy because constitutional rights, representative institutions, coalition bargaining, expert administration and competing interests can constrain policy choices. Public opinion is therefore an important source of political information and legitimacy, but it is not identical to government policy or to a binding legal instruction.
Measuring public opinion presents conceptual problems because people do not always have fully formed views on every issue. Some respondents choose an answer because a survey asks them to take a position on a topic they have never previously considered. Question wording, response options, question order and survey mode can influence answers. Researchers therefore distinguish between measuring an underlying attitude and measuring a response produced partly by the survey instrument. A well designed survey attempts to minimise such measurement effects through clear wording, appropriate response options, testing and consistent methodology.
