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Formalization of the General Hypothesis

The overlap between personal social environments allowed us to reconstruct the social landscape of Esslingen. This event structure aggregates reports from historical sources about memberships in institutions, committees, social clubs and single events, events prior to the protest phase. Aggregating these historical observations into a general structure of city events, treats the observations as time independent and persistent. Individual change, which in the extreme can be a movement between opposing political clusters of events, shows up as a link between these in the aggregation.

Trying to understand how the exposure in the personal environment contributes to political activity needs additional assumptions in this case. We have to assume that not only existing co-memberships contribute to the degree of exposure, but also that the political orientation of the people met at former events has an impact on the individual "political" career. Though this is true only for relatively few cases, the extent to which these additional assumptions are necessary is clearly unfavorable for an empircial test of the relationship between the degree of exposure and political protest.

To examine and test the general hypothesis that activity in the Petition Movement is a function of the exposure to actors already active, we further need to define and operationalize the concepts of activity and exposure. The activity for each actor is defined as the number of petitions he has signed within each of the three periods. The degree of exposure is defined as the number of contacts a person has to others already active in the Petition Movement.

This allows to study the overall diffusion process cross-sectionally, how activity at a given point in time is related to the distribution of activists in the overall structure of events and whether each single individual behaves according to the amount of exposure he experiences in this personal social environment.


Figure 3 Exposure to Activists:

Activists, Events and Exposure



The logic of this definition and its operationalization is illustrated in Figure 3. We distinguish between a set of activists (A1 to A8) who are already actively involved in the petition movement and events (E1 to E4), that link them to other actors (P1 to P5) who have not yet participated in the Petition Movement. Through a set of social events activists are linked to those who are not yet active at that time. How does the participation in events and the contacts to other activists translate in our measure of exposure? Let us again consider an example: P4 in Figure 2 has the highest degree of exposure among all non-activists. P4 participates in two events and through these events is linked to 6 activists. Although P2 and P3 at the same time participated in two events, they only come in contact with three activists (P3 actually met up with only two activists since he met one person twice, but we count this as three contacts) and hence have a lower degree of contacts. Calculating the amount of contacts for each actor at any given point in time, yields to a combined measure of the intensity of contact and hence of exposure. This individual degree of exposure is different for each of the three phases, depending on how many individuals a given actor is linked to through his participation in the events of the overall structure.


From network considerations one would expect a great intensity of contact among those people who are most active within the city's events. In contrast, those who do not actively participate in the social life are less likely to have a high degree of exposure. Though this relationship holds true in general, a low activity does not necessarily imply a small degree of contacts and exposure. Consider the following case as an illustration: An actor participates in only one event, but this event concentrates an in-numerous amount of activists. The result will be a high degree of exposure. Thus, expansivity alone is not a necessary condition for a high exposure, although the two generally go hand in hand.

next up previous contents
Next: A First, Visual Insight Up: Exposure, Networks, and Mobilization: Town Previous: The Events as Context