Enhancing the Face Validity of Choice Experiments: a Simple Diagnostic Check

We propose a simple diagnostic check for face validity assessment of willingness to pay (WTP) estimates derived from choice experiments (CEs). The check is based on a threshold value for WTP that is related to the highest cost attribute level, which can be used to assess plausibility of estimated WTP. If the threshold value is exceeded, WTP estimates are considered to overshoot. This may be due to issues with (i) the design of the CE and/or (ii) respondents’ behavior deviating from assumptions underpinning CEs. Applying the check to a sample of publications, this paper provides evidence on the incidence and magnitude of overshooting of WTP in the agricultural and environmental CE literature. Based on a random sample of publications including 304 observations representing individual studies and population samples, the results show that overshooting of WTP is widespread, with 65% of observations exceeding the overshooting threshold value. An exploratory analysis to identify factors associated with overshooting of WTP across studies reveals that study design factors, and in particular the design of the cost attribute, play an important role. We recommend that researchers apply the diagnostic check for the design of choice experiments and to motivate further scrutiny of choice experiment results

Do we care about sustainability? An analysis of time sensitivity of social preferences under environmental time-persistent effects

This research work has been conducted under the Training Program for University Professors of the Spanish Ministry of Education, Culture and Sport (AP2010-3810). The authors are also grateful for the funds awarded by the Government of the Balearic Islands through the Special Action Program (AAEE025/2012) and for the financial support from the CICYT Program of the Spanish Government (ECO2010-22143).Environmental cost-benefit analysis has traditionally assumed that the value of benefits is sensitive to their timing and that outcomes are valued higher, the sooner in time they occur following implementation of a project or policy. Though, this assumption might have important implications especially for the social desirability of interventions aiming at counteracting time-persistent environmental problems, whose impacts occur in the long- and very long-term, respectively involving the present and future generations. This study analyzes the time sensitivity of social preferences for preservation policies of adaptation to climate change stresses. Results show that stated preferences are time insensitive, due to sustainability issues: individuals show insignificant differences in benefits they can experience within their own lifetimes compared to those which occur in the longer term, and which will instead be enjoyed by future generations. Whilst these results may be specific to the experimental design employed here, they do raise interesting questions regarding choices over time-persistent environmental problems, particularly in terms of the desirability of interventions which produce longer-term benefits.PostprintPeer reviewe

A FEW NOTES ABOUT THE BELL-TOWER OF THE ST. DOMINIC CHURCH IN DUBROVNIK

The article deals with the final stage of the construction of the bell-tower belonging to the Church of St. Domenic in Dubrovnik, the construction as such having been studied by Cvito Fisković. The to-day’s Baroque top of the bell-tower was added in the course of repairs executed following the damages caused by earthquakes in the 17th and 18th centuries. Concentrating his attention on two marginal notes contained in a document from 1443 (publiched by Fisković), the authoress is particularly attracted by a detail in the history of tower-building by stages, trying to find out the probable appearance of the original 15th century top stage that had been destroyed. The study bases on records newly discovered in the archives. According to a statement contained in a contact dated in March, 1944, we find that the bell-tower was completed at that time. Some light is thrown by that document on the bell-tower belonging to the up to now uncertainly located cathedral church of St. Mary at Ulcinj, known only from sources. Master Peter, a Dominican friar, and his son Nicholas, glazier and vitroist, signed a contract undertaking to build the top stage of the mentioned bell-tower patterned after the Dubrovnik one. The appearance of the pre-earthquake bell-tower at Dubrovnik is not known, but it may be reconstructed from a few sources and pictures of Dubrovnik from the time before the earthquake. The height of the top stage amounted to 7 metres, which lent to the tower a Gothic accent – an alongated four-sided pyramid without adornments. From old panoramic views of Dubrovnik, we know that the bell-tower top was covered, but whether it was with stone slabs or lead sheets, or tiles, we cannot say. The authorship of the Dubrovnik tower is finally questioned in the article, i. e. whether is had been built by the mentioned friar Peter, who, thanks to the experience gained, was later invited to construct also the top section of the bell-tower of the Ulcinj cathedral

Economic valuation of ecosystem goods and services: a review for decision makers

There is increasing interest in the use of economic valuation of ecosystem goods and services for a wide variety of purposes. These include relatively familiar uses in project appraisal and more novel applications in advocacy, performance tracking and accounting in public and private settings. Decision makers who use valuation information need to understand the background, strengths and weaknesses of these approaches. The methods have a strong foundation in economic theory and offer a rapidly growing evidence base, improving ability to evaluate a broad range of ecosystem goods and services. Nevertheless, there are theoretical and practical limitations that need to be understood and kept in mind when interpreting results. In this paper, we briefly review the economic valuation methods and situate them in their historical and theoretical contexts. We assess the main critiques, attempts at resolving them, and implications for the usefulness of the methods in different contexts. We examine the main barriers and opportunities for wider uses of valuation evidence, and draw conclusions on the appropriate role of valuation in future, as a tool for aiding reflection and deliberation processes

Challenges in economic valuation of wetland protection under climate change impacts

[eng] The conservation of humid lands emerges as a priority within the social debate. Given the contribution of wetlands to sustain human well-being, their protection in the face of increasing anthropogenic stresses is perceived as socially desirable. This is especially true in the face of climate change (CC), which is expected to become the major source of wetlands’ deterioration in the future. In this sense, to be welfare-maximizing, policy design should be guided by knowledge about the valuation of the social benefits of wetlands’ protection. In this framework, while the valuation task becomes a crucial tool to better inform policymakers, it is also associated with some challenges. These are due to the fact that CC is a future time-persistent problem and its impacts are expected to be complex, inherently uncertain and extended over the long- and very long-term. Regardless of the fact that these aspects are anticipated to affect social welfare, their role in stated preference valuation has been largely underexplored. To shed some light on these issues, three are the research questions addressed in this thesis. First, the trade-offs between the social value of avoiding different and complex wetland impacts. Second, the effect on the social preferences for preservation measures of incorporating information about the inherent uncertainty of environmental processes. Third, the role of sustainability issues by examining whether social preferences for policies having their benefits in the long- and very long-term are non-declining. To answer these questions, a choice experiment has been undertaken in S’Albufera wetland (Mallorca, Spain). In specific, the valuation exercise has been designed to consider: separate attributes for the complex impacts of CC, alternative scenarios of probability of impacts’ occurrence to express inherent uncertainty and different time horizons in the long- and very long-term. Results have shown that complexity, inherent uncertainty and sustainability issues are relevant aspects. Individuals overall care about the impacts of CC on wetlands, even though they assign unequal values to the different impacts considered, suggesting substitution and complementarity patterns that are useful for the design of environmental policies. Respondents are sensitive to the inherent uncertainty associated with the natural variability of CC effects. They also care about sustainability issues, by equally valuing preservation in the long-term and very long-term, due to a concern for the well-being of future generations. These findings are important not only to better inform wetland management under CC, but also to guide stated preference valuation practitioners. Indeed, results show that the challenges associated with valuation in the face of time-persistent environmental problems, like CC, need to be carefully considered, given that ignoring them can have important social welfare implications.[spa] La conservación de las zonas húmedas ocupa un lugar central en el debate social. Y es que dada su contribución al bienestar humano y ante la creciente presión antropogénica, su protección se percibe hoy día como socialmente deseable. Este hecho adquiere, si cabe, más importancia ante el cambio climático (CC), un fenómeno que se prevé se convierta en la principal fuente de deterioro de los servicios ecológicos que proporcionan las zonas húmedas. Así las cosas, en un intento de maximizar el bienestar social, resulta fundamental apoyar la toma de decisiones públicas con un conocimiento detallado de las preferencias sociales y, en particular, del valor que la sociedad asigna a la protección de estas zonas. En este contexto, a pesar que la valoración económica resulta una herramienta fundamental para mejorar la toma de decisiones, no hay que obviar que lleva implícitos importantes desafíos. No en balde, el CC es un problema persistente en el tiempo y sus efectos son, por definición, complejos, inherentemente inciertos y se extienden desde el presente al futuro más cercano y más lejano. Todos estos aspectos, independientemente de la influencia que se espera tengan en el bienestar social, han sido poco explorados en los estudios de valoración basados en preferencias declaradas. En este sentido, en un intento de mostrar la influencia que ejercen estos aspectos en los ejercicios de valoración económica, el presente trabajo gira alrededor de tres preguntas. En primer lugar, se examinan los componentes del valor social de políticas encaminadas a evitar los complejos y variados impactos del CC. En segundo lugar, se estudia el efecto que la incorporación de información sobre la incertidumbre inherente a los procesos ecológicos tiene sobre las preferencias sociales. Y en tercero y último lugar, se analizan cuestiones relacionadas con la sostenibilidad, y concretamente, si las preferencias sociales por políticas que tienen beneficios en el largo plazo y muy largo plazo son no-decrecientes. Para abordar estas cuestiones, se ha realizado un experimento de elección en la zona húmeda de S’Albufera (Mallorca, España). En particular, el ejercicio de valoración se ha diseñado teniendo en cuenta: diferentes atributos para capturar la complejidad de los impactos del CC, escenarios alternativos de probabilidad de ocurrencia de los impactos, para expresar la incertidumbre inherente a los procesos ecológicos, y diferentes horizontes temporales. Los resultados han mostrado que la complejidad, la incertidumbre inherente y la sostenibilidad son aspectos relevantes. En general, los individuos se preocupan por los impactos del CC en las zonas húmedas, aunque asignan valores diferentes a los atributos considerados, sugiriendo patrones de sustitución y complementariedad útiles a la hora de diseñar políticas ambientales. Así mismo, se confirma que los individuos son sensibles a la incertidumbre inherente asociada a la variabilidad natural de los efectos del CC, a la vez que se muestran sensibles a las cuestiones relacionadas con el bienestar de las generaciones futuras, valorando igual la preservación en el largo plazo como en el muy largo plazo. Estos resultados son importantes no sólo para informar la gestión de zonas húmedas en un contexto de CC, sino también para guiar los expertos de valoración basados en preferencias declaradas. De hecho, los resultados confirman que los desafíos específicos asociados a problemas ambientales persistentes, como el CC, se deben tener en cuenta en los ejercicios de valoración.[cat] La conservació de les zones humides ha esdevingut un tema rellevant en el debat social. I és que atesa la seva contribució en el benestar humà, la seva protecció davant la creixent pressió antropogènica es percep avui dia com a socialment desitjable. Aquest fet adquireix, si cal, més importància davant el canvi climàtic (CC), un fenomen que es preveu es converteixi en la principal font de deteriorament dels serveis ecològics que proporcionen les zones humides. Així les coses, en un intent de maximitzar el benestar social, esdevé fonamental recolzar la presa de decisions públiques amb un coneixement detallat de les preferències socials i, en particular, del valor que la societat assigna a la protecció d’aquestes zones. En aquest context, tot i que la tasca de valoració econòmica esdevé una eina fonamental per a millorar la presa de decisions, no cal obviar que també du implícits importants desafiaments. No debades, el CC és un problema persistent en el temps i els seus efectes són, per definició, complexos, inherentment incerts i s’estenen des del present al futur més proper i més llunyà. Tots aquests aspectes, independentment de la influència que s’espera tinguin en el benestar social, han estat poc explorats en els estudis de valoració basats en preferències declarades. En aquest sentit, en un intent de mostrar la influència que exerceixen aquests aspectes en els exercicis de valoració econòmica, el present treball gira al voltant de tres punts. En primer lloc, s’examinen els components del valor social de polítiques encaminades a evitar els complexes i variats impactes del CC. En segon lloc, s’estudia l’efecte que la incorporació d’informació sobre la incertesa inherent als processos ecològics té sobre les preferències socials. I en tercer i darrer lloc, s’analitzen qüestions relacionades amb la sostenibilitat, i concretament, si les preferències socials per polítiques que tenen beneficis en el llarg termini i en el molt llarg termini són nodecreixents. Per abordar aquestes qüestions, s’ha realitzat un experiment d’elecció en la zona humida de S’Albufera (Mallorca, Espanya). En particular, l’exercici de valoració s’ha dissenyat tenint en compte: diferents atributs per capturar la complexitat dels impactes del CC, escenaris alternatius de probabilitat d’ocurrència dels impactes, per expressar la incertesa inherent als processos ecològics, i diferents horitzons temporals. Els resultats suggereixen que la complexitat, la incertesa inherent i la sostenibilitat són aspectes rellevants. En general, els individus es preocupen pels impactes del CC en les zones humides, encara que assignen valors diferents als atributs considerats, tot suggerint patrons de substitució i complementarietat útils alhora de dissenyar polítiques ambientals. Així mateix, es confirma que els individus són sensibles a la incertesa inherent associada amb la variabilitat natural dels efectes del CC i, alhora, es mostren sensibles a les qüestions relacionades amb el benestar de les generacions futures, valorant igual la preservació en el llarg termini com en el molt llarg termini. Aquests resultats són importants no només per informar la gestió de zones humides en un context de CC, si no també per guiar els experts en exercicis de valoració basats en preferències declarades. De fet, els resultats mostren que els desafiaments específics associats a problemes ambientals persistents, com el CC, s’han de tenir en compte en els exercicis de valoració