Changing Patterns of Recreation over Time: What Can Be Learned from Panel Studies? Thomas A. Heberlein Department of Rural Sociology University of Wisconsin-Madison-USA Walter F. Kuentzel School of Natural Resources University of Vermont-USA Rebecca A. Grossberg Department of Rural Sociology University of Wisconsin-Madison-USA Please Do Not Cite without Permission Updated Versions at http://nature.snr.uvm.edu/ai/ Introduction Final June 28, 1999 The title of this paper is misleading. It suggests a dry dusty methodological treatise on the virtues of using panel data. Usually in these papers the authors have no real data but give clear examples of what might be learned IF time series or panel data were available. Because it takes a long time commitment, substantial and sustained resources, institutional stability, and a dose of good luck to collect data on individuals over time there are many more what if papers than what is papers. This paper, which began 24 years ago in a small National Park in the United States is the real thing. Today we will be reporting the first glimpses of what one can see with longitudinal data from three cross-sectional surveys, a three-wave panel and a two-wave panel of visitors to a North American National Park. We surveyed visitors to the Apostle Islands National Lakeshore in 1975, 1985, and 1997. We also surveyed the 1975 visitors 10 years and 22 years after they were first surveyed, and surveyed the 1985 visitors 12 years after they were first sampled. A true understanding of growth and change requires time-series data. As Stynes and Driver (1990) note, "the research questions raised by the leisure benefits area dictated methods that many leisure scientists were not very experienced with, such as, experimental and longitudinal designs." There have been repeated calls from public sector managers and private sector industry officials for trend data on recreation participation. The growth of outdoor recreation in the 1970s along with growth in domestic and international tourism in the 1980s has created a need for a historical perspective that projects the future of recreation and leisure from an understanding of the past. In response, researchers have sponsored four Trends Conferences in Outdoor Recreation between 1980 and 1995. More than 100 papers were presented at the 1990 conference, but only a handful presented findings from time-series data. The use of time-series data increased somewhat in the 1995 conference, although most of these studies relied on multiple cross-section designs. Overall, little panel data exists in the recreation research field, and even fewer panels extend beyond five years. Many researchers have lamented the lack of longitudinal data. Louviere and Timmermans' (1990) review of the recreation choice literature asserts that "all of the preceding types of models historically have been strictly cross-sectional: preferences or choices are observed and modeled at a single point in time. Unfortunately, such data may not be sufficiently rich to distinguish and estimate the effects of the many sources of influence on choice behavior. Consequently, interest in longitudinal or panel data has increased considerably and models of dynamic choice behavior have been proposed." Similarly, Hellerstein and Mendelsohn review research on the economic impacts of travel and note that "...knowledge could be gained by going beyond this 'single snapshot' of the world, by augmenting the experiment with multiple samples. One obvious source for different samples is in the time dimension -- with different samples gathered at different points in time. While exceptions exist (e.g., Peterson & Stynes, 1985), the potential of multi-year data has not been exploited by travel cost modelers." What little panel data exists in the recreation literature tends to utilize a pretest/post-test design. These studies tend to cover a period spanning a few months, and seldom cover more than five years at a time. Page -2- Final June 28, 1999 Design of the Apostle Islands Study In 1970 the US Congress designated 20 Islands in Lake Superior on the North coast of Wisconsin as the Apostle Islands National Lakeshore. This resource was to be managed by the National Park Service as a National Recreation Area. For the most part, National Lakeshores are like National Parks except that they are open to more diverse recreation (like hunting) than other national parks. The park began acquiring property from the state and private individuals in 1971, and had their first operational budget of $68,000 in 1972. In 1975 the senior author along with graduate assistant Jerry Vaske designed a visitor survey of those who boated to, camped on, or visited the Islands. The explicit goal of this study was to follow up both the 1975 visitors over time to see how they reacted as the new park developed. We were explicitly interested in crowding and visitor displacement. Would the development of the Park crowd out the current visitors and would they be replaced by a new set of less sensitive visitors? This research was funded by the UW-College of Agriculture Experiment Station. The new unit in the Park Service was struggling to become operational and were hard pressed to study potential future problems. The 1975 study used various listing procedures (Heberlein and Vaske, 1979) to locate and census boaters, campers, and day visitors during that summer. After the season those who filled out census cards were sent a mailed questionnaire asking them to describe their activities, their activities on a best trip and their expectations, perceptions, and satisfactions. This was the first cross section. Completed questionnaires were returned from 649 of the boaters (74% response). This became the first (1975) cross-section survey of Apostle Island visitors. In 1985 the number of boater camper nights (the NPS estimate of the number of people who moored or docked their boat at one of the islands over night) had increased from 7117 in 1976 to 15,828 in 1985. The other two groups, campers and day visitors, had remained about stable. Consequently the 1985 survey was focused only on the boating group. The survey was funded by the Wisconsin Sea Grant Institute. This time we stationed samplers on islands at randomly selected times throughout the boating season. In the evening, these samplers would approach all anchored or docked boats who were staying the night, and collect names and addresses of all passengers over 16 on each boat. At the end of the season, a sample of these boaters were sent mailed surveys. The sample was stratified by the island where individuals were registered, and was proportionate to total overnight use at each island and by peak season and shoulder seasons at the Park. Because people who boat more days are more likely to fall in the sample, the final data were inversely weighted by boater days. 500 questionnaires were mailed to boaters and 377 were returned for a response rate of 75.4 %. This became the second (1985) cross-section. In addition 500 of the 648 respondents from 1975 were relocated and mailed a survey to determine what they had been doing since 1975. Of the 500 people located, 397 returned questionnaires in 1985 (79.4%) , so we have a 1975-85 panel surveys of the same Page -3- Final June 28, 1999 people at two points in time. Trudy McKinnel and Laurie Erwin were research assistants on this project. In 1997 Walt Kuentzel, who had done his dissertation on the Apostle Islands data, and was an Assistant Professor at the University of Vermont was a co-principal investigator and supervised the field work and constructed the surveys. The same sampling methodology employed in 1985 was used again in 1997. Interviewers were stationed on specific islands to approach all boats anchored or docked overnight to register all visitors over 16 years old. A sub sample of these registered boaters were then selected to receive a follow-up questionnaire. Again, the selection process was proportionately stratified by total overnight use at each island and by seasonal use at the Islands. Rebecca Grossberg at the University of Wisconsin supervised the 1997 survey administration. A 32 page questionnaire was sent to 562 people registered in 1997 and 389 were returned for a 69.2% percent response rate. These responses comprised the third (1997) cross- section survey. In addition, 409 of the 649 respondents in 1975 were located and mailed surveys. Of these 249 were returned for a 60.9% response rate. This produced the third wave of the 1975- 1997 panel. Next, 327 of the 377 respondents in 1985 were located and mailed surveys. Among these groups 160 were returned for 48.9% response rate. This produced the second wave of a 1985-1997 panel. Finally, there was a new group of boaters visiting the islands in 1997 sea kayakers. A special survey was sent to 191 overnight sea-kayakers we registered during 1997. Of these, 103 surveys were returned for a 53.9% response rate. For a detailed discussion of the 1997 methodology see Appendix 1 Results and Discussion Multiple time series studies and panel studies provide at least three types of information that are distinct from the information provided by a single cross-sectional or qualitative case study. First are the major unobserved changes that catch people off guard, and that may be a driving force behind the social system. Change is obviously unavailable in single cross-sectional studies except as individuals use retrospective reflections to assess change. Longitudinal data allows one to monitor structural changes that may escape individual scrutiny. Second, there are things that remain remarkably constant over time in spite of dramatically different and changing populations. Finally are the things that simply require time for processes to unfold.