Panel Paper: Linking Collaborative Institutions To Environmental Outcomes: A Multilevel, Longitudinal Analysis Of The Relationship Between Water Quality and Collaborative Watershed Management

Friday, November 8, 2013 : 1:15 PM
Plaza II (Ritz Carlton)

*Names in bold indicate Presenter

Tyler Scott, University of Washington

In this paper I examine how the form and structure of collaborative management relates to environmental outcomes. In what follows, I briefly describe the theoretical rationale for this research. I then describe my sample frame and the data used to conduct this analysis. Finally, I detail the multilevel statistical model used to test how specific collaborative management policy characteristics at both the watershed and state level relate to water quality and watershed health.


One of the most frequent applications of government-supported collaboration is in watershed management, largely because the complexity of watershed management and the diversity of relevant stakeholders. However, there is little empirical evidence regarding whether collaborative management actually improves the environmental condition of watersheds. In order to efficiently use public resources and maximize environmental benefits, it is important to base collaborative management choices on demonstrated impacts. Thus, in this paper I examine how these specific policy design and implementation decisions affect the environmental impact of collaborative watershed management.

Research Design

I use watershed condition data from a representative sample of 600 large rivers sampled in the eastern United States as part of the EPA’s 2008-2009 National Rivers and Streams Assessment (NRSA). I then collect data and code specific variables that represent basic group characteristics (e.g., group size, year of formation) as well as variables used to test the following hypotheses: 

H1: An increased level of collaborative watershed management group responsibility (whether group is designated an information sharing forum, a planning group, or a policy implementation body) results in better water quality outcomes.

H2: Increased plan and objective formalization for collaborative watershed management results in better water quality outcomes

H3: Inclusiveness and diverse representation in collaborative watershed management results in better water quality outcomes.

I employ a multilevel model that accounts for variation at the watershed and state level. At the first level of the model I estimate a water quality index score  for individual river i in state j:

Υji = αj + βjCji + ΣkηkCollabkjiCji + ΣlδlRivCharlji + ΣlγlRivCharljiCji + ΣpτpStresspji + ΣpρpStresspjiCji + εji

where αj represents the conditional state mean estimate for non-collaborative watersheds; βj estimates the conditional impact of collaboration by state (Cji is a binary indicator of collaborative watershed management for river i in state j); RivCharlji represents a vector of river characteristics (1 to l); Collabkji represents a vector of collaborative management characteristics (1 to k); Stresspji represents a vector of watershed stressors (1 to p); and εji represents the river random error term.

 The conditional state impact is the dependent variable for the second model level:

 βj = β0 + ΣmπmStateCharmj + μj

in which equals the effect of state characteristic (1 to m); and μj equals the state random error term. A third regression term (also at the state level) models the conditional non-collaborative outcome at the state level as a function of the same vector of state characteristics:

αj = α0 + ΣmλmStateCharmj + νj

This multilevel model will test the hypotheses above by examining the coefficient estimates (ηk) for each coded collaborative watershed management characteristic (1 to k). Additionally, I test interactions between management choices and specific watershed stressors to examine context-specific implications.

Full Paper: