A linkage institution is a structure within a society that connects the people to the government or centralized authority. These institutions include: elections, political parties, interest groups, and the media.
Development
Government is formed as a legitimate alternative to violence. These governments create policy making institutions to develop rules by which conflicts within society are to abide by. Democratic governments often elect a legislative body. Monarchies develop a single arbitrator. Aristocracies develop a privileged body of individuals. All of which centralized authority, develop an institutionalized structure, and provides a means by which policy is made. Dynamic social change occasionally require rules within a society to change. Linkage institutions provide the means to connect those individuals within a society to the centralized authority.
Political exclusions and oligarchical tendencies within societies create "linkage failures". These events create contentions within society and act as motivators towards social protests and rebellion.