Recreation demand analysis under truncation, overdispersion, and endogenous stratification: an application to Gros Morne National Park

Using on-site survey data from Gros Morne National Park in Newfoundland, this paper estimates and compares several truncated count data models of recreation demand. The selected model accounts not only for the truncated and overdispersed nature of the data but also for endogenous stratification due to the oversampling of avid users. Moreover, the model that allows for a flexible specification of the overdispersion parameter dominates on the basis of goodness of fit. The results are used to estimate the users' value of access to the park.     

Markov Modulated Poisson Processes for Clustered Line Transect Data

We model the points of the detection along the transect line by a Markov modulated Poisson process (MMPP). The MMPP can accommodate the spatial cluster structure typical of many line transect surveys. The basic idea is that animal density switches between a low and a high level according to a latent Markov process. The MMPP is attractive from a mathematical point of view, as it provides an explicit expression for the likelihood function and other important quantities. We focus on estimating the level of overdispersion in the number of detected animals, as this is important for quantifying the precision of the line transect estimator of animal abundance. The approach is illustrated using both simulated data and data from a minke whale sighting survey conducted in the North Atlantic. Received: August 2004 / Revised: August 2005