This column is a summary of my recently published book which explores the under-theorized role of informal institutions in socio-political life. It proposes a novel, multi-dimensional classification of informal institutions, identifying four new types. The study further argues that formal institutions' exclusionary nature and resulting legitimacy deficits promote the emergence of informal institutions. Moreover, changes in formal institutional effectiveness or legitimacy, evolving socio-political cultures, and shifting power dynamics among actors are likely to drive informal institutional change. The study illustrates these ideas using four empirical cases from the Turkish case.

Under-theorized Role of Informal Institutions

While informal institutions significantly influence socio-political life, institutional analyses have historically prioritized formal institutions, defined as codified rules, procedures, and regulations that are “created, communicated, and enforced through channels widely accepted as official” (Helmke and Levitsky 2004: 727). Early institutional studies, by concentrating on the "tip of the iceberg," failed to illuminate the substantial, often invisible, role of informal institutions, which refer to “socially shared rules, usually unwritten, that are created, communicated, and enforced outside of officially sanctioned channels” (Helmke and Levitsky 2004: 727). Consequently, informal institutional factors and mechanisms remain relatively understudied and undertheorized. This persistent focus on formal institutional arrangements, which are more structured and visible than informal rules, has resulted in an incomplete understanding of socio-political life.

Recent institutional literature has acknowledged the pervasive influence of informal rules and mechanisms in socio-political life (e.g., Helmke and Levitsky 2004; Tsai 2007). However, despite this recognition, the existing theoretical literature on informal institutions lacks a comprehensive conceptual framework. The existing studies primarily offer ad hoc generalizations and partial theoretical accounts. Thus, compared to formal institutions, informal institutions still remain undertheorized.

Addressing this theoretical gap, the book examines the role of informal institutions in socio-political life by focusing on the following research questions: How can informal institutions be classified? Why and how do informal institutions emerge? Finally, what factors drive informal institutional change?

Novel Types of Informal Institutions

To address these research questions, this book introduces a novel multidimensional typology of informal institutions. This typology identifies four distinct types of informal institutions: (1) symbiotic, (2) superseding, (3) layered, and (4) subversive. To illustrate each type, the book empirically analyzes four cases of informal institutions as derived from the Turkish socio-political context.

In case of symbiotic type, there is a mutually-beneficial relationship between formal and informal institutions. Informal religious marriage in Türkiye constitutes a prime example of symbiotic informal institutions. Although not officially recognized and thus not legally required, close to 90% of marriages involve both formal civic marriage and informal religious marriage. This is because while formal marriage offers legal rights and protection, informal religious marriage adds religious legitimacy to the union, hence fostering a symbiotic relationship.

Superseding informal institutions emerge when agents find the existing formal rules as harmful to their self-interests and as illegitimate. Thus, such institutions supersede or transcend weak formal rules and regulations. As an example of superseding informal institution, this study examines the Cem courts of Türkiye’s Alevi community. Cem courts, the main conflict resolution forum within the Alevi religious minority, function as informal communal justice institutions. Convened during the Cem, the main Alevi religious ritual, these courts address various disputes among Alevis. Alevis were marginalized under the Ottoman Empire, which followed the Hanefi school of Sunni Islam. Thus, instead of using Ottoman courts led by kadıs applying Islamic and customary law, Alevis turned to Cem courts. These practices persisted into the early secular Republic. Until urbanization in the 1950s–60s, Cem courts dominated Alevi dispute resolution, superseding formal litigation. In contemporary Turkish society, however, Cem courts function as a complementary informal institution rather than as a superseding one.

Regarding layered informal institutions, in some cases, actors might abide by formal rules and regulation but they do not necessarily view them as legitimate, rightful and just. Failing to amend the existing illegitimate formal rules, they might set up or resort to relatively more legitimate informal institutions, informally operating next to the existing formal rules and regulations. In case of layered informal institutions, formal and informal institutions would constitute a multilayered institutional structure. In such multilayered institutional terrains, there might be occasional tensions or frictions between those formal and informal institutional layers. Religious minority holidays in the Turkish context constitute an illustrative example of layered informal institutions. The Turkish state officially recognizes only Sunni Islamic holidays (Eid al-Fitr and Eid al-Adha), reflecting the country's dominant religious culture. As a result, holidays celebrated by religious minorities, including non-Muslims (e.g., Christmas, Easter) and Alevis (e.g., Day of Ashura, Gadir Hum), have an informal, de facto status. Thus, Muslim and non-Muslim religious minority groups in Türkiye informally observe and celebrate their holidays. As a result, these holidays exist solely in the informal domain as overlapping layers.

Subversive informal institutions emerge as a result of the nonbeneficial and illegitimate formal arrangements. Certain actors (individual or collective) might view the existing formal arrangements as ‘illegitimate’ and ‘harmful’ in terms of their ideational or material interests. Failing to remove or amend those illegitimate and detrimental formal institutions, they might establish or resort to informal arrangements and practices to contest and resist exclusionary formal arrangements. One might expect such informal institutions to be widespread especially among groups or movements excluded or marginalized by the existing sociopolitical system. These informal institutions are contentious, destructive and sometimes seditionist informal institutions. Multilingual municipalism initiated by the Kurdish ethnopolitical movement in Türkiye is an emblematic case of subversive informal institutions. As a key informal institution, the Kurdish ethnopolitical movement's multilingual municipalism in Türkiye directly challenges exclusionary formal rules. Since 2007, pro-Kurdish municipalities have resisted the official Turkish-only language policy by delivering services in various local languages like Kurdish, Arabic, Armenian, and Syriac, aiming to expand rights for the Kurdish ethnic minority and undermine the state's homogenous linguistic agenda.

The Emergence and Evolution of Informal Institutions

Regarding the emergence of informal institutions, existing research indicates that several factors and dynamics increase the likelihood of their emergence. These include: the failure or reluctance of agents to establish formal institutions, the incompleteness of existing formal rules, the rigidity or inefficiency of formal institutions, and the ambiguity of formal rules. The current study further argues that the presence of exclusionary or discriminatory formal institutions, leading to a legitimacy deficit, also promotes the emergence of informal institutions. Particularly in restrictive regimes, formal legal systems often reflect the norms of the dominant majority, excluding minority cultures and identities. This exclusion diminishes the legitimacy of formal institutions among marginalized groups. The restrictive nature of formal rules in these regimes compels excluded minorities to establish or utilize informal institutions, which may either conflict or cooperate with formal arrangements.

With respect to changes in the existing informal institutions, informal institutional change is likely to be triggered by factors such as shifts in the effectiveness and/or legitimacy of formal institutions, changes in the socio-political culture, and evolving power structures among institutional actors.

Summary

In sum, the informal sphere of socio-political life, akin to an iceberg's hidden bulk, greatly influences the formal. Beyond their direct influence, informal institutions shape socio-political processes by interacting with formal rules in diverse ways, including cooperation and competition. Therefore, understanding socio-political dynamics requires accounting for these often-overlooked informal factors.

This study stresses institutional legitimacy, a factor often neglected in institutional analyses that focus on efficiency and effectiveness (e.g., Helmke and Levitsky 2004). Informal institutions influence the legitimacy of formal ones, alongside their efficiency and effectiveness. The Turkish case shows that even efficient formal institutions can lack legitimacy, prompting informal arrangements. Hence, formal institutional legitimacy impacts both their performance and the rise and development of informal institutions.

Author’s Note

This column is based on Sarigil, Zeki. 2023. How Informal Institutions Matter: Evidence from Turkish Social and Political Spheres. Ann Arbor: University of Michigan Press.

References

Helmke, Gretchen, and Steven Levitsky. 2004. "Informal Institutions and Comparative Politics: A Research Agenda." Perspectives on Politics 2 (04): 725-740.

Sarigil, Zeki. 2023. How Informal Institutions Matter: Evidence from Turkish Social and Political Spheres. Ann Arbor: University of Michigan Press.

Tsai, Kellee S. 2007. Capitalism Without Democracy: The Private Sector in Contemporary China. Ithaca: Cornell University Press.

Author’s Profile

Zeki Sarigil is a Professor at the Department of Political Science, Bilkent University. He was also a Visiting Research Fellow at IDE-JETRO in 2025.

* Thumbnail image: Turkish Flag and Mosque just above the Bosphorus/ The Image Bank (Darrell Gulin/ Getty Images)
**The views expressed in the columns are those of the author(s) and do not represent the views of IDE or the institutions to which the authors are attached.

©2025 Zeki SARIGIL

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