Weighted programming: A programming paradigm for specifying mathematical models

We study weighted programming, a programming paradigm for specifying mathematical models. More specifically, the weighted programs we investigate are like usual imperative programs with two additional features: (1) nondeterministic branching and (2) weighting execution traces. Weights can be numbers but also other objects like words from an alphabet, polynomials, formal power series, or cardinal numbers. We argue that weighted programming as a paradigm can be used to specify mathematical models beyond probability distributions (as is done in probabilistic programming). We develop weakest-precondition- and weakest-liberal-precondition-style calculi à la Dijkstra for reasoning about mathematical models specified by weighted programs. We present several case studies. For instance, we use weighted programming to model the ski rental problem - an optimization problem. We model not only the optimization problem itself, but also the best deterministic online algorithm for solving this problem as weighted programs. By means of weakest-precondition-style reasoning, we can determine the competitive ratio of the online algorithm on source code level

Evaluating Strategies for Packaging Travel

Packaging has been a popular means of selling travel for over a century and in no small way has been responsible for the development of mass markets. In the light of this, it is surprising to find that there has been little research into the packaging phenomenon, especially from the point of view of an evaluation of packaging strategies. Principally, the literature documents flows of packaged travel or trends in sales. Very few researchers have attempted to model consumer preferences for packages. This paper reviews previous published work on packaging, but then characterises it as a form of price bundling, the general term used in marketing to describe a strategy of tying the sale of one product to the purchase of another. This more general framework is used to explain strategic motivations for popular packaging methods with an emphasis on consumers' decision-making in the presence of bundles. The paper examines the claim that the travel package, and especially the fully-inclusive tour, is at an advanced stage in its product life-cycle and that it will provide little stimulus to further growth in travel. The bundling paradigm suggests that unbundling travel can succeed, but there will remain a place for packaged travel products

MT SCORP: Facility and Natural Resource Recreation Area Needs: Facility Manager Responses 2012

A survey of local, state, federal, school and tribal mangers were surveyed to understand the quantity and quality of outdoor recreation facilities and area needs. This study was conducted for use in the State Comprehensive Outdoor Recreation Plan process

ISER Working Paper 2009.1

In this report we calculate the economic importance of nature-based tourism in Southeast Alaska as measured by business revenue. Our estimates are based on field research conducted during 2005, 2006 and 2007. We define nature-based tourism as those tourism activities for which the natural environment is a significant input.1 Our key findings include the following: • Nature-based tourism generates about $277 million per year of direct business revenues in Sitka, Juneau, Chichagof Island, Prince of Wales Island, Petersburg and Wrangell. This number is most likely an underestimate of total revenues because not all naturebased tourism businesses and business sectors could be included in our estimates. Our numbers do not include tips – which in some businesses might add 25taxes and fess paid directly to local governments. In addition, the especially rainy weather of 2006 probably caused abnormally low sales for some businesses. • Average revenue per visitor varies considerably among communities and activities; ranging from about$140 per visitor in Juneau to more than $2,600 per visitor on Prince of Wales Island. These differences reflect the range of activities offered -- from half-day excursions to multiple, overnight all-inclusive lodge stays. • Nature-based tourism expenditures create a significant economic ripple effect that keeps money circulating through the economy. This money supports jobs in marketing, support services, food and beverages, accommodations, fuel sales, government, and other sectors. • Communities are clearly striving to differentiate themselves and capitalize on local amenities such as the Stikine River, Anan Creek, the LeConte Glacier, Tracy Arm, Glacier Bay, Pack Creek and exceptional fishing and scenic opportunities. • A large and growing portion of Southeast Alaska’s visitors are cruise ship passengers. Both cruise passengers and independent travelers are similarly interested in nature-based tourism services. The majority of cruise ship shore excursions offer nature-based activities, from hikes and glacier viewing to flightseeing and forest canopy zip lines. • Communities hosting large numbers of cruise passengers are actively developing new and creative tourism products such as forest canopy zip lines and mountain biking while those with fewer visitors tend to be focused on sport fishing. This appears to be the case even if local amenities exist to support a broader range of business and visitor activities. Thus, there appear to be unrealized opportunities in some communities, but these may also reflect an inadequate visitor base upon which to risk additional investment. • There is a complex and competitive system for pre-booking cruise ship shore excursions. Businesses with exclusive cruise line contracts make price and tour information available only to cruise passengers and often agree to sell tours only through the cruise line.• The tourism businesses in cruise ports of call that appear to be most successful either have a cruise ship shore excursion contract or are catering to overnight (non-cruise) guests with high-quality and high-value services. Examples of these types of businesses include sport fishing lodges and multi-day yacht cruises. • It is difficult to compete with established businesses holding existing cruise line contracts. Despite this hurdle, a number of companies are offering creative new products including zip lines through the forest canopy, glass-bottomed boats, and an amphibious “duck” tour. • Some operators attribute the increased interest in adventure activities to a change in cruise ship clientele. In recent years, cruise companies have been catering to a younger crowd, targeting families. In any event, increasing numbers of passengers are interested in more active pursuits. • Competition for cruise passengers exists both within and between communities, as people are booking their shore excursions in advance and look at all the options. Sitka companies mentioned they were carefully tracking zip line activity in Juneau and Ketchikan, dogsled tours on the Mendenhall Glacier, and other activities to see which market niche they could capture. • There is some evidence that visitors are willing to pay premium prices for higher quality experiences in more pristine environments. However, it is not clear what specific attributes (seclusion, fishing experience, food, services, perceived exclusivity, and environmental amenities) are the key components of this higher market value. • It is possible to design a community-based tourism program that provides employment to local residents as is occurring in Hoonah. However, Elfin Cove appears to bring in more in gross revenues than Hoonah with about one-eighth as many visitors because Hoonah’s operation relies on volume while Elfin Cove businesses rely on higher-priced fishing lodge experiences. Day trips seem to be relatively higher cost, lower profit operations. • Independent travelers appear to try to avoid crowds and many are repeat visitors. Most tend to stay longer and have more open itineraries than those on cruise ships or organized tours. These characteristics make independent travelers more difficult to contact. • Independent travelers also appear to seek communities with fewer visitors and those that they perceive to be more “authentic,” such as Petersburg, Wrangell, and communities on Chichagof Islands. A lack of transportation capacity, whether on scheduled jets or on ferries, may be limiting the opportunities for these smaller communities. Less marketing may also be a factor limiting visits by independent travelers. • The primary marketing mechanisms for smaller, non-cruise related businesses are the internet and word of mouth. In addition, many customers return to the same fishing lodge, yacht tour, or charter business year after year. • Wildlife viewing is highly attractive to visitors due to spectacular scenery and abundant wildlife including whales and other marine mammals. Companies in several communities expressed a desire to move toward more wildlife viewing and sightseeing and away from sport fishing. These operators preferred wildlife viewing as it was less stressful due to less pressure to catch fish. Some operators were making this shift, while others thought they would not be able to match the revenue generated by sport fishing. • Weather has a significant impact on business for companies whose tours are not prebooked on cruise ships. Operators noted a marked difference between the sunny, dry summer of 2004 and the remarkably wet summer of 2006. Visitors walking off a ship in the rain were much less likely to go on marine tours or hikes in soggy conditions, and seasonal revenues were down. Businesses with cruise contracts did not experience this setback as passengers are not reimbursed for pre-sold tours when weather conditions are poor. The one exception was flightseeing, where companies had to cancel tours due to unsafe weather conditions. • Promoting wildlife watching is an important marketing strategy for Southeast Alaska communities. Visitors bureaus currently produce pamphlets with charismatic large animals, such as whales and bears. Bureau staff cited studies showing the desire to see wildlife was attracting a large portion of out-of-state visitors. • A significant policy question emerging from this research is how the public lands might be managed to increase the economic returns from tourism to residents of Southeast Alaska communities, especially the smaller communities that can only accommodate smaller numbers of visitors at one time. Bear viewing is one example of a high-value activity that depends on controlled access to specific infrastructure.Alaska Conservation Foundation. University of Alaska Foundation. The Wilderness Society.Executive Summary / Introduction / Methods / Ketchikan / Juneau / Sitka / Norther Southeast Alaska Yachts / Chichagof Island / Prince of Wales Island / Petersburg / Wrangell / Conclusion

Estimating demand for environmental goods and services, now and later

This dissertation presents three papers that estimate the demand for environmental goods and services. Chapter 1 begins with a brief overview of the practice of nonmarket valuation, with discussion of previous applications and the methods that I advance in the subsequent chapters. I also provide a common nomenclature for continuity in understanding, the underlying intuition and motivation, and discussion of the results throughout. In chapter 2, I examine the behavioral response of winter recreationists to marginal changes in mountain snowpack. I make three primary contributions in this chapter: 1) I develop a new method to estimate elasticities for climate amenities by matching the spatial and temporal variation in the level of the amenity with the frequency of related market transactions; 2) I derive state-specific snowpack elasticities for all major markets across the United States and find significant heterogeneity in the behavioral response across states; and 3) I estimate year-to-year variation in the recreation revenue from snowpack under current and future climate scenarios. I predict that resort markets could face reductions in local snow-related revenue of -40\% to -80\%, almost twice as large as previous estimates suggest. In chapter 3, I extend the analysis from the previous chapter to estimate utility functions for winter recreationists in the United States. I make two primary contributions in this chapter: 1) I estimate the marginal willingness to pay (MWTP) for mountain snowpack at the national and regional levels; and 2) I construct a matrix of substitution elasticities between resort markets. Both contributions invoke random utility maximization to estimate structural parameters in the utility functions of alpine skiers. For the first contribution (1), I maintain trip-level data to estimate marginal utilities and subsequent MWTP. I address price endogeneity concerns using an instrumental variables approach. For the second contribution (2), I aggregate the trip-level data to market-level and calculate daily market shares. This allows me to recover substitution patterns that provide insight into how skiers move across markets based on marginal changes in mountain snowpack. Each of these are important for understanding consumer welfare in the alpine skiing market and the implications under a changing climate. In chapter 4, I examine preferences for surface water quality and quantify some overlooked benefits of nutrient reductions in the Mississippi River Basin. Improvements in local surface water quality in the Mississippi River Basin (MRB) can contribute to the regional environmental goals of reducing hypoxia in the Gulf of Mexico. To inform estimates of the benefits of water quality policy, I use a choice experiment survey in a typical sub-watershed of the MRB to estimate willingness to pay for local environmental improvements and helping to reduce hypoxia far downstream. I find that residents place large values on reduced local algal blooms, improved local fish populations and diversity, and meeting local commitments to help with the regional environmental problem. I conclude my analysis in chapter 5 by providing a clear summary of my findings and why they are important. I discuss some of the possible implications for the benefits that I quantify and list a few examples of how they can be used when generating climate and environmental policy

Casco Bay Weekly : 16 November 1989

https://digitalcommons.portlandlibrary.com/cbw_1989/1046/thumbnail.jp