Integrated bio-economic models as tools to support land-use decision making: a review of potential and limitations

Bio-economic modelling has become a useful tool for anticipating the outcomes of policies and technologies before their implementation. Advances in mathematical programming have made it possible to build more comprehensive models. In an overview of recent studies about bio-economic models applied to land-use problems in agriculture and forestry, we evaluated how aspects such as uncertainty, multiple objective functions, system dynamics and time have been incorporated into models. We found that single objective models were more frequently applied at the farm level, while multiple objective modelling has been applied to meet concerns at the landscape level. Among the objectives, social aspects are seldom represented in all models, when being compared to economic and environmental aspects. The integration of uncertainty is occasionally a topic, while stochastic approaches are more frequently applied than non-stochastic robust methods. Most multiple-objective models do not integrate uncertainty or sequential decision making. Static approaches continue to be more recurrent than truly dynamic models. Even though integrating multiple aspects may enhance our understanding of a system; it involves a tradeoff between complexity and robustness of the results obtained. Land-use models have to address this balance between complexity and robustness in order to evolve towards robust multiple-objective spatial optimization as a prerequisite to achieve sustainability goals.     

Qualitätserwartungen und ethischer Anspruch bei der Lektüre von Blogs und von Tageszeitungen

Besides classical journalistic products, media users increasingly tend to read texts on the internet published by other users, as in weblogs. How do users navigate among these offers, how do they evaluate the quality, and which standards in terms of media ethics do they apply when reading weblogs compared to newspaper articles? Two empirical studies address these questions. In a survey, 702 internet users rated their theoretical expectations in terms of journalistic quality and compliance with ethical standards, comparing weblogs and daily newspapers. In a consecutive 2 × 2 experimental design, 120 participants read a journalistic text with varying source information (weblog/daily newspaper) and varying degree of adherence to ethical standards (ethically questionable/neutral). Participants then rated the quality of the text and its ethical standards. Results indicate that daily newspapers more than blogs are expected to deliver journalistic quality. But when read, texts are evaluated according to their content rather than their source. Ethically questionable texts in newspapers are disapproved as much as ethically questionable blog postings.     

An alternative interpretation of multiple bounded WTP data—Certainty dependent payment card intervals

This paper analyzes the multiple bounded format, in which uncertainty is directly incorporated into the WTP question. A new approach for analyzing multiple bounded uncertainty data is presented. The intuition underlying the approach is that uncertain individuals would like to state their WTP as intervals rather than precise values and that the width of the intervals is determined by the degree of uncertainty. The approach is compared to the one applied in Welsh and Poe [Welsh, M., Poe, G.L., 1998. Elicitation effects in contingent valuation: comparisons to a multiple bounded discrete choice approach. Journal of Environmental Economics and Management 36, 170–185] which treats uncertainty by conditioning responses on specific verbal probability statements. We argue that the conditioning approach overestimates mean and median WTP and that conditioning WTP estimates on probability statements like “probably” and “unsure” make them “fuzzy”. To empirically compare the two approaches we use data from 2004 concerning implementation of a predator protection policy in Sweden. Our analysis show that the suggested approach: (1) is more intuitive; (2) better fits the data; (3) estimates mean and median WTP with better precision; (4) is less sensitive to distributional assumptions; and (5) it is better suited for policy analysis.     

The LeChatelier-Samuelson principle revisited

Within the context of a linear Leontief model, the LeChatelier-Samuelson principle examines the effects of an increase in some final demand on the output levels under the constraint that the production of certain goods is held at its original value. The principle states that the increase in any output is larger when fewer output levels are kept constant. The present paper discusses bounds for such incremental changes, second-order effects, the consequences on the markets for the products with restricted output levels, and generalizations of the original assumptions.I would like to thank two anonymous referees for their helpful comments.     

On invariant parametric covariance families

Summary In this note we characterize all linear transformations of random vectors which are invariant for a given parametric covariance family. Two one-dimensional covariance families are discussed in detail.     

The effects of debt versus equity inflows on savings and growth in developing economies

Zusammenfassung Die Wirkung von ausl?ndischer Kapitalbeteiligung und Kreditfinanzierung auf Ersparnisbildung und Wachstum in Entwicklungsl?ndern. — Zur Bew?ltigung der internationalen Schuldenprobleme von Entwicklungsl?ndern wird h?ufig vorgeschlagen, die Struktur des Kapitalimports zugunsten von Forderungsarten zu verschieben, bei denen sich die Gl?ubiger am wirtschaftlichen Risiko beteiligen, wie dies etwa bei Direktinvestitionen der Fall ist. Die Wahl zwischen Kapitalbeteiligung und Kreditfinanzierung mag jedoch Risiko-Ertrag-Konflikte zwischen Einkommensstabilit?t und erwartetem wirtschaftlichem Wachstum involvieren. Diese Hypothese wird aus einem entscheidungstheoretischen Modell auf der Basis eines Benutzer-Eigentümer Verh?ltnisses abgeleitet und mittels einer L?nderquerschnittsuntersuchung regressionsanalytisch getestet. Es zeigt sich, da\ bei nichtkooperativen Beziehungen zwischen Schuldnern und Gl?ubigern kreditfinanzierte Kapitalimporte einen vergleichsweise starken positiven Einflu\ auf die Ersparnisbildung und das Wirtschaftswachtum im Schuldnerland ausüben. Kapitalbeteiligungen k?nnen deshalb nicht ohne weiteres als vorteilhaft angesehen werden und auch nicht allen L?ndern empfohlen werden, ohne zu bedenken, wie sich soziale Gruppen gegenüber dem Risiko verhalten.

---

Résumé Les effets de l’influx de la dette et du capital propre sur l’épargne et la croissance en économies développantes. — L’élément commun des beaucoup de propositions données pour faciliter les problèmes de la dette extérieure des pays développants est l’intention de changer la structure des importations de capital vers l’augmentation du rapport des créances qui basent sur quelque forme de partager les risques, p.e. la participation en capital propre. Cependant, le choix entre le capital propre ou des influx des capitaux financés par des dettes peut induire un conflit de ?rendement-risque? entre la stabilité de revenu et la croissance attendue. Cette hypothèse est dérivée d’un modèle choix-théorique basé sur l’approche agent-principal et testée empiriquement en appliquant l’analyse de régression trans-pays. Les auteurs démontrent que, dans un cadre non-coopératif des relations débiteurcréditeur, des transferts financés par des dettes ont une influence plus positive sur l’épargne et la croissance économique. La participation en capital propre ne peut pas être évaluée supérieure sans ambigu?té et c’est pourquoi elle ne peut pas être recommendée pour tous les pays, indépendant des attitudes sociales envers le risque.

---

Resumen El efecto del endeudamiento sobre el ahorro y el crecimiento eneconomías en desarrollo comparado con el de las inversiones directas. — En varias propuestas para aliviar el problema de la deuda externa de los países en desarrollo se sugiere alterar la composición de las importaciones de capital en el sentido de aumentar la proportión de derechos con participación en el riesgo económico, es decir, la participación de la inversión directa. La elección entre inversión directa y deuda considera la relación inversa riesgo-beneficio que existe entre la estabilidad del ingreso y el crecimiento esperado. Esta tesis se dériva de un modelo teórico de elección basado en el enfoque agente-principal, que es sometido a un test empírico de regresión sobre una muestra de países. Se muestra que en el marco de relaciones deudor-acreedor de tipo no cooperativas las transferencias de financiamiento por deuda ejercen una influencia positiva relativamente superior sobre el ahorro y el crecimiento económico. La participación directa en el capital no resulta superior en todos casos y por ello no puede ser recomendada para todos los países, independientemente de las actitudes frente al riesgo que prevalezcan.