American Political Science Review Vol.94,No.2 and political changes over time,self-reinforcing dy- the attractiveness of existing institutional arrangements namics associated with collective action processes relative to hypothetical alternatives.As social actors mean that organizations have a strong tendency to make commitments based on existing institutions and persist once they are institutionalized. policies,their cost of exit from established arrange- ments generally rises dramatically. The Institutional Density of Politics As much recent work in political science stresses, Political Authority and Power Asymmetries efforts to coordinate actors in the pursuit of public In the famous community power debate of the 1960s goods often require the construction of formal institu- and 1970s.Bachrach and Baratz (1962)and Lukes tions.Once established,these institutional constraints (1974)argued persuasively that power asymmetries are can apply to all-those who do not approve as well as often hidden from view;where power is most unequal, those who do-and they are backed up,ultimately,by it often does not need to be employed openly.Pluralist force.The exit option,so central to the workings of the critics essentially countered that a systematic evalua- market,is often unavailable (or prohibitively costly)to tion of such claims was impossible (Polsby 1963; actors who feel poorly served by existing political Wolfinger 1971).Although he does not frame the issue arrangements.In politics,institutional constraints are quite this way,Gaventa (1980)demonstrates that ubiquitous.Politics involves struggles over the author- power asymmetries can reflect the operation of positive ity to establish,enforce,and change the rules governing feedback processes over substantial periods.Increasing social action in a particular territory.In short,much of returns processes can transform a situation of relatively politics is based on authority rather than exchange. balanced conflict,in which one set of actors must Both formal institutions (such as constitutional ar- openly impose its preferences on another set ("the first rangements)and public policies place extensive,legally face of power"),into one in which power relations binding constraints on behavior. become so uneven that anticipated reactions ("the Although unorthodox,the inclusion of public poli- second face of power")and ideological manipulation cies as well as formal institutions in this formulation is ("the third face")make open political conflict unnec- important (Pierson 1993).Policies are generally more essary.Thus,positive feedback over time simulta- easily altered than the constitutive rules of formal neously increases power asymmetries and renders institutions,but they are nevertheless extremely prom- power relations less visible. inent constraining features of the political environ- The allocation of political authority to particular ment.Policies,grounded in law and backed by the actors is a key source of this kind of positive feedback coercive power of the state,signal to actors what has to Indeed,this represents a source of path dependence be done and what cannot be done,and they establish quite distinct from those discussed by Arthur and many of the rewards and penalties associated with North.When certain actors are in a position to impose particular activities.Most policies are remarkably du- rules on others,the employment of power may be rable (Rose 1990).Especially in modern societies, self-reinforcing (Mahoney 1999).Actors may use po- extensive policy arrangements fundamentally shape the litical authority to generate changes in the rules of the incentives and resources of political actors. game (both formal institutions and various public That such institutions are prone to increasing returns policies)designed to enhance their power.Relatively is implicit in much recent research on institutions. small disparities in political resources among contend- Scholars emphasize how institutions can help actors ing groups may widen dramatically over time as posi- overcome various dilemmas arising from collective tive feedback sets in. choice situations-especially the need to coordinate their behavior by disciplining expectations about the behavior of others.What is absent or downplayed, The Complexity and Opacity of Politics however,is a recognition that these characteristics Economic theory is built in large part around the useful render processes of institutional development path and plausible assumption that actors seek to optimize dependent. and are relatively good at it.Firms operate to maximize As already discussed,North highlights how institu- profits.The metric for good performance is relatively tions induce self-reinforcing processes that make rever- simple and transparent.Prices send strong signals that sals of course increasingly unattractive over time.In facilitate the analysis of how various features of the contexts of complex social interdependence,new insti- economic environment affect firm performance.Ob- tutions and policies are costly to create and often servable,unambiguous,and often quantifiable indica- generate learning effects,coordination effects,and tors exist for many of these features.Workers can adaptive expectations.Institutions and policies may encourage individuals and organizations to invest in to mean previous outlays that cannot be recovered and should be specialized skills,deepen relationships with other indi- regarded as irrelevant to current choices among options.The whole viduals and organizations,and develop particular po- point of path dependence,however,is that these previous choices litical and social identities.14 These activities increase often are relevant to current action.In cases of increasing returns, social adaptations represent investments that yield continuing bene- fits.Actors may be locked into a current option because massive new 14 It is common to refer to such consequences as sunk costs. investments may be required before some theoretically superior Although intuitive,this terminology is unfortunate.Economists use it alternative generates a higher stream of benefits. 259