Theme C: Social Norms


In this part of the project, we study how social norms interact with the natural environment to foster cooperation that overcomes common-pool dilemmas.



Project 1: The Creation of Social Norms under Weak Institutions


Authors: Florian Diekert, Tillmann Eymess, Joseph Luomba, Israel Waichman




Abstract: Preventing the exploitation of natural resources in developing countries is a typical situation where policies have to rely on norm-based interventions to improve outcomes. Yet, little is known about how different social norms can be created in repeated and strategic situations. Our lab-in-the-field experiment (N=588) studies how information about high or low levels of previous cooperation affects the creation of social norms in a three-player prisoner's dilemma game with/without social sanctioning. 
Providing different social information succeeds in creating different norms of cooperation, but only if a sanctioning opportunity is available. When the initial information emphasizes cooperation, cooperation rates start high and stay high and when the initial information emphasizes defection, cooperation rates start low and stay low. Cooperation rates decline without social sanctioning, irrespective of the initial information. Exploring the role of the reference network, we find that initial information is more effective the stronger the social proximity among participants.


Status: Submitted. Current draft of manuscript available on request: Write to



Project 2: Dissecting Social Norms of Cooperation


Author: Tillmann Eymess


Graphical Abstract: Dissecting Social Norms


Abstract: Norm-nudges and sanctioning mechanisms can induce behavioral change. In combination, the two measures are however sparsely tested and the underlying behavioral mechanism is poorly understood. With a conditional process analysis, I focus on the interplay between norm-nudge and sanctioning and study the drivers of behavioral change when both measures are combined.
Results suggest that norm-nudges induce a behavioral change in two ways. First, their effect on cooperation is, in part, mediated by empirical expectations. Those who receive information about cooperative behavior of others, expect them to cooperate and subsequently cooperate themselves. Second, norm-nudges directly affect cooperation when combined with a sanctioning opportunity. Moreover, I highlight the methodological importance to explore causal paths via the inclusion of contextual variables in the framework of social information, norm conformity, and behavioral change.


Status: Submitted. Current draft of manuscript available on request: Write to



Project 3: Changing Collective Action


Authors: Florian Diekert and Tillmann Eymess




Abstract: We test whether a norm-based intervention increases cooperation when decisions are taken by teams, not individuals. Teams in our experiment are crews from fishing boats at Lake Victoria, Tanzania.
We randomize two decision making mechanisms (majority voting and the choice of a random team member) across social information treatments. This allows identifying experience with hierarchical or egalitarian decision structures, both present at Lake Victoria. Providing information on the behavior of previous teams increases average cooperation by 14 and 19 percentage points for egalitarian and hierarchical team decisions, respectively. Further, captains from boats with hierarchical organization are particularly responsive to the norm-based intervention.


Status: Current draft of manuscript available on request: Write to



Project 4: Overcapitalization and social norms of cooperation in a small-scale fishery


Authors: Robbert Schaap, Andries Richter

Graphical Abstract Social Norms-1

Abstract: The increasing technological efficiency of harvesting equipment has been identified as one of the main causes of overcapacity and overexploitation of natural resources. In this paper, a formal model is developed which studies the effects of technological efficiency as an endogenous variable within a bioeconomic system. We model capital investments in a fishery, where investment decisions are made less frequently than the allocation of variable inputs. We study how the possibility to invest in capital affects open access dynamics, and also the evolution of cooperative harvesting norms. We find that the possibility to make large capital investments can destabilize cooperation, especially if enforcement capacity is low. Further, we find that communities can preserve cooperation by agreeing on a resource level that is lower than socially-optimal. This reduces the incentive to deviate from the cooperative strategy and invest in capital.


Status: Published in Ecological Economics, vol. 166 - LinkExterner Inhalt



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Letzte Änderung: 17.03.2021
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