Page 128 5— Design Principles for TCMs We study history to learn from past experience. To a recreation demand modeler this means we build TCMs to analyse what visitors did, so we can learn what they will do in the future. But we don't build a TCM just to predict what visitors will do if current trends continue. We build it to find out what they will do under one or more proposed policies. Then, if we are good listeners and good communicators, we explain those predictions to decisionmakers so that they can formulate an appropriate set of decisions among the many possible choices they face. Building models ensures that our data are organized so that we can exploit its relationships. We then use our knowledge of those historical relationships to predict the past and thus check the usefulness of the model by comparing the predictions with our knowledge of what actually occurred. If the predictions are good, we are able to design better futures provided the structure doesn't change. This book assumes that models will normally be quantitative and estimated through regression models. What it means to predict the past accurately needs little elaboration. We use the independent variables of our TCM regression model in conjunction with its algebraic function to predict the behavior we actually saw. We want to estimate a TCM for which price, income, site characteristics and demographic factors predict recorded trips. We can use the model then to construct counterfactual histories of the past by...
You are not authenticated to view the full text of this chapter or article.
Elgaronline requires a subscription or purchase to access the full text of books or journals. Please login through your library system or with your personal username and password on the homepage.
Non-subscribers can freely search the site, view abstracts/ extracts and download selected front matter and introductory chapters for personal use.
Your library may not have purchased all subject areas. If you are authenticated and think you should have access to this title, please contact your librarian.