Biological markets: supply and demand determine the effect of partner choice in cooperation,mutualism and mating

The formation of collaborating pairs by individuals belonging to two different classes occurs in the contexts of reproduction and intea-specific cooperation as well as of inter-specific mutualism. There is potential for partner choice and for competition for access to preferred partners in all three contexts. These selective forces have long been recognised as important in sexual selection, but their impact is not yet appreciated in cooperative and mutualistic systems. The formation of partnerships between members of different classes has much in common with the conclusion of trade agreements in human markets with two classes of traders, like producers and consumers, or employers and employees. Similar game-theoretical models can be used to predict the behaviour of rational traders in human markets and the evolutionarily stable strategies used in biological markets. We present a formal model in which the influence of the market mechanism on selection is made explicit. We restrict ourselves to biological markets in which: (1) Individuals do not compete over access to partners in an agonistic manner, but rather by outcompeting each other in those aspects that are preferred by the choosing party. (2) The commodity the partner has to offer cannot be obtained by the use of force, but requires the consent of the partner. These two restrictions ensure a dominant role for partner choice in the formation of partnerships. In a biological market model the decision to cooperate is based on the comparison between the offers of several potential partners, rather than on the behaviour of a single potential partner, as is implicitly assumed in currently accepted models of cooperation. In our example the members of one class A offer a commodity of fixed value in exchange for a commodity of variable value supplied by the other class, B. We show that when the B-class outnumbers the A-class sufficiently and the cost for the A-class to sample the offers of the B-class are low, the choosiness of the A-class will lead to selection for the supply of high value commodities by the B-class (Fig. 3a). Under the same market conditions, but with a high sampling cost this may still be the evolutionariy stable outcome, but another pair of strategies proves to be stable too: relaxed choosiness of class A coupled with low value commodities supplied by class B (Fig. 3b). We give a number of examples of mating, cooperative and mutualistic markets that resemble the low sampling cost situation depicted in Fig. 3a.     

Removal of contaminants in leachate from landfill by waste steel scrap and converter slag

This study may be the first investigation to be performed into the potential benefits of recycling industrial waste in controlling contaminants in leachate. Batch reactors were used to evaluate the efficacy of waste steel scrap and converter slag to treat mixed contaminants using mimic leachate solution. The waste steel scrap was prepared through pre-treatment by an acid-washed step, which retained both zero-valent iron site and iron oxide site. Extensive trichloroethene (TCE) removal (95%) occurred by acid-washed steel scrap within 48 h. In addition, dehalogenation (Cl⁻ production) was observed to be above 7.5% of the added TCE on a molar basis for 48 h. The waste steel scrap also removed tetrachloroethylene (PCE) through the dehalogenation process although to a lesser extent than TCE. Heavy metals (Cr, Mn, Cu, Zn, As, Cd, and Pb) were extensively removed by both acid-washed steel scrap and converter slag through the adsorption process. Among salt ions (NH₄⁺, NO₃⁻, and PO₄³⁻), PO₄³⁻ was removed by both waste steel scrap (100% within 8 h) and converter slag (100% within 20 min), whereas NO₃^- and NH₄⁺ were removed by waste steel scrap (100% within 7 days) and converter slag (up to 50% within 4 days) respectively. This work suggests that permeable reactive barriers (PRBs) with waste steel scrap and converter slag might be an effective approach to intercepting mixed contaminants in leachate from landfill.     

Structure and Operation of a Bushmeat Commodity Chain in Southwestern Ghana

Abstract:  The bushmeat trade is perceived as a major threat to wild animal populations in the tropics. Little is known of how the trade is organized, however, or of the actors involved in it, impeding the development of effective conservation policy. We investigated the structure and operation of a bushmeat commodity chain in West Africa that supplies a typical urban market, the city of Takoradi in southwestern Ghana. Data were collected from January through February 2000, describing 2430 bushmeat transactions encompassing 17 different taxa from 70 different actors, through a combination of direct observation and semistructured interviews. Five different types of actor traded along the commodity chain: commercial hunters, farmer hunters, wholesalers, market traders, and chopbar (cafe) owners. Bushmeat was traded freely among all these actors, although the primary trade route for terrestrial mammals was from commercial hunters via wholesalers to chopbars. In contrast, invertebrates were only traded by farmer hunters, market traders, and chopbars. Wholesalers captured the largest per capita share of the market (4% of all sales were handled by each wholesaler), whereas the most important vendors were chopbars, which as a group made 85% of all bushmeat sales to the public. Variation in the price of bushmeat was largely explained by transport costs and taste preferences. Transport costs were most significant for hunters and greatest on long journeys involving large loads. Nevertheless, hunters obtained the greatest income per kilogram of bushmeat sold of all actor groups. Our results suggest that there is no single best entry point along the bushmeat commodity chain for conservation intervention. On the contrary, the successful monitoring and management of the bushmeat trade is likely to require a multiactor approach that encompasses most or all actor groups.     

Thin versus Thick CO2 Market

The idea that trading is more costly the thinner the market is is common in most studies of market exchange with frictions. Surprisingly, this element is lacking from previous attempts to allow for frictions in pollution permit markets. This paper considers a CO₂ cap-and-trade model where trading costs develop endogenously as a function of the market size. The pre-trade allocation of permits determines whether the market size can be strongly influenced by expectations that have a role because of adjustment costs. The pre-trade allocation also sets preconditions for endogenously vanishing trading costs and thus has nonstandard effects on long-run trading levels and market allocations.     

Legal ivory trade in a corrupt world and its impact on African elephant populations

Illegal hunting of African elephants (Loxodonta africana) for ivory is causing rapid declines in their populations. Since 2007, illegal ivory trade has more than doubled. African elephants are facing the most serious conservation crisis since 1989, when international trade was banned. One solution proposed is establishment of a controlled legal trade in ivory. High prices for ivory mean that the incentives to obtain large quantities are high, but the quantity of tusks available for trade are biologically constrained. Within that context, effective management of a legal ivory trade would require robust systems to be in place to ensure that ivory from illegally killed elephants cannot be laundered into a legal market. At present, that is not feasible due to corruption among government officials charged with implementing wildlife‐related legislation. With organized criminal enterprises involved along the whole commodity chain, corruption enables the laundering of illegal ivory into legal or potentially legal markets. Poachers and traffickers can rapidly pay their way out of trouble, so the financial incentives to break the law heavily outweigh those of abiding by it. Maintaining reliable permitting systems and leak‐proof chains of custody in this context is challenging, and effective management breaks down. Once illegal ivory has entered the legal trade, it is difficult or impossible for enforcement officers to know what is legal and illegal. Addressing corruption throughout a trade network that permeates countries across the globe will take decades, if it can ever be achieved. That will be too late for wild African elephants at current rates of loss. If we are to conserve remaining wild populations, we must close all markets because, under current levels of corruption, they cannot be controlled in a way that does not provide opportunities for illegal ivory being laundered into legal markets. Comercio Legal de Marfil en un Mundo Corrupto y su Imapacto sobre Poblaciones de Elefantes     

Siting Noxious Facilities: Are Markets Efficient?

This paper explores the economics and politics of the siting of noxious facilities. In the base case, facilities are sited by markets, subject to majority agreement in the host jurisdiction. By contrast with the existing market siting literature-which assumes that all the disamenities of a facility will be contained in the host jurisdiction and fully reflected in the jurisdiction′s willingness to accept-here facilities impose disamenities on individuals as a function of distance, and the process of majority agreement is explicitly modeled. The principal finding is that when voters are uniformly distributed within a jurisdiction, an individual who is median distance from a facility suffers less than average (mean) disamenity. Therefore a majority would be willing to serve as facility host for a price (host fee) that is strictly less than the aggregate disamenity that the facility imposes on the jurisdiction. Further, by threatening the equilibrium host with a site just across its border, a firm can induce majority acceptance of a nontrivial facility at zero host fee. Even when this threat site strategy is infeasible, though, market-determined host fees will not signal efficient sites. Thus, markets will produce an excessive number of noxious facilities and place them in the wrong sites. These results are robust to alternative specifications of bargaining power and market structure. If, however, host majority agreement is subject to the veto of a higher jurisdiction-e.g., in response to cries of "NIMBY"-then efficiency may be either improved or reduced.     

Double-dipping in environmental markets

There is an increasing tendency to use markets to induce the provision of environmental services. As such markets increase in scope, potential market participants might sell multiple environmental services. The question we consider here is whether participants in such markets should be allowed to sell credits in more than one market simultaneously. Some have argued in favor of such “double-dipping”, because it would make the provision of environmental services more profitable. In practice however, most programs do not allow double-dipping. We show that if the optimal level of pollution abatement is sought, then double-dipping maximizes societal net benefits. However, if pollution policies are set in a piecemeal fashion, then the caps for each market are unlikely to be optimal and, in this second-best setting, a policy prohibiting double-dipping can lead to greater social net benefits. We explore conditions under which a single-market policy is preferred, or equivalently, where piecemeal policies are likely to yield particularly inefficient outcomes.     

Correlates of bushmeat in markets and depletion of wildlife

We used data on number of carcasses of wildlife species sold in 79 bushmeat markets in a region of Nigeria and Cameroon to assess whether species composition of a market could be explained by anthropogenic pressures and environmental variables around each market. More than 45 mammal species from 9 orders were traded across all markets; mostly ungulates and rodents. For each market, we determined median body mass, species diversity (game diversity), and taxa that were principal contributors to the total number of carcasses for sale (game dominance). Human population density in surrounding areas was significantly and negatively related to the percentage ungulates and primates sold in markets and significantly and positively related to the proportion of rodents. The proportion of carnivores sold was higher in markets with high human population densities. Proportion of small‐bodied mammals (<1 kg) sold in markets increased as human population density increased, but proportion of large‐bodied mammals (>10 kg) decreased as human population density increased. We calculated an index of game depletion (GDI) for each market from the sum of the total number of carcasses traded per annum and species, weighted by the intrinsic rate of natural increase (r_max) of each species, divided by individuals traded in a market. The GDI of a market increased as the proportion of fast‐reproducing species (highest r_max) increased and as the representation of species with lowest r_max (slow‐reproducing) decreased. The best explanatory factor for a market's GDI was anthropogenic pressure—road density, human settlements with >3000 inhabitants, and nonforest vegetation. High and low GDI were significantly differentiated by human density and human settlements with >3000 inhabitants. Our results provided empirical evidence that human activity is correlated with more depleted bushmeat faunas and can be used as a proxy to determine areas in need of conservation action.     

Use of Market Data to Assess Bushmeat Hunting Sustainability in Equatorial Guinea

Abstract: Finding an adequate measure of hunting sustainability for tropical forests has proved difficult. Many researchers have used urban bushmeat market surveys as indicators of hunting volumes and composition, but no analysis has been done of the reliability of market data in reflecting village offtake. We used data from urban markets and the villages that supply these markets to examine changes in the volume and composition of traded bushmeat between the village and the market (trade filters) in Equatorial Guinea. We collected data with market surveys and hunter offtake diaries. The trade filters varied depending on village remoteness and the monopoly power of traders. In a village with limited market access, species that maximized trader profits were most likely to be traded. In a village with greater market access, species for which hunters gained the greatest income per carcass were more likely to be traded. The probability of particular species being sold to market also depended on the capture method and season. Larger, more vulnerable species were more likely to be supplied from less‐accessible catchments, whereas there was no effect of forest cover or human population density on probability of being sold. This suggests that the composition of bushmeat offtake in an area may be driven more by urban demand than the geographic characteristics of that area. In one market, traders may have reached the limit of their geographical exploitation range, and hunting pressure within that range may be increasing. Our results demonstrate that it is possible to model the trade filters that bias market data, which opens the way to developing more robust market‐based sustainability indices for the bushmeat trade.     

Non-compliance and the quota price in an ITQ fishery

This paper examines the effects of non-compliance on quota demands and the equilibrium quota price in an ITQ fishery. I show that whereas lower quota prices are implied unambiguously by expected penalties which are a function of the absolute violation size, the expectation of penalties based upon relative violations of quota demands can, under certain conditions, produce higher quota prices than in a compliant quota market. If there are both compliant and non-compliant firms in the fishery, the result would then be a shift in quota demand from compliant to non-compliant firms, rather than the reverse. The findings are generally applicable to quota markets in other industries, including pollution permit markets.     

Political influence on non-cooperative international climate policy

We analyze non-cooperative international climate policy in a setting of political competition by national interest groups. In the first stage, countries decide whether to link their domestic emission permit markets to an international market, which only forms if it is supported by all countries. In the second stage, countries non-cooperatively decide on the number of tradable emission allowances. In both stages, special interest groups try to sway the government in their favor. We find that (i) both the choice of regime and the levels of domestic and global emissions only depend on the aggregate levels of organized stakes in all countries and not on their distribution among individual interest groups and (ii) an increase in lobbying influence by a particular lobby group may backfire by inducing a change towards the lobby group's less preferred regime.     

Price uncertainty and the exhaustive firm

In the presence of a resource constraint the risk-averse exhaustive firm reacts to price uncertainty in a manner different than its competitive counterpart. In particular: (i) some results are independent of attitudes toward risk; (ii) comparative statics results differ from the no resource constraint case; and (iii) results depend upon the relative magnitudes of the discount rate and quasi-fixed costs. An assumption crucial to the relevance of risk-aversion in an intertemporal setting is the presence of imperfections in capital markets (i.e., the absence of complete contingent commodity markets).     

Measuring values for environmental resources under uncertainty

The relationship between conventional Hicksian measures of the benefits from changes in environmental amenities under certainty, and corresponding measures of valuation when the conditions of access to an uncertain environmental resource are changed, is considered. The analysis utilizes a contingent commodity framework with the assumption of state-dependent preferences. The findings suggest that the valuation of these changes will depend upon the availability of fair markets for diversifying risk. Moreover, conventional measures of compensating or equivalent surplus will not necessarily bound the individual's valuation of a change in access to an uncertain environmental resource.     

Strategy and management for the recycling of carbon fiber-reinforced polymers (CFRPs) in the aircraft industry: a critical review

ABSTRACT

Carbon fiber-reinforced polymers (CFRPs) have attracted attention from the aerospace industry due to their light weight, excellent mechanical properties, and resistance to corrosion. However, CFRP composites are difficult to recycle as their recycling process must be performed under extreme conditions; end-of-life regulations do not directly address the problem with reusing these composites. Thus, the objective of this study is to explore solutions that minimize the use of CFRPs and prolong their useful life in the airline industry. To achieve this goal, this work conducted a review of the state of the art of CFRP fiber recycling, emphasizing the recycling processes, restrictions, and regulations. One solution is to develop a CFRP recycling market that would allow the sequential use of recycled materials among industries in descending order of the required structural performance of the composite.     

The Reuse of Urban and Industrial Waste in Tai-Lin-Pu Reclamation Project, Taiwan

This study introduces the principles of KMG's (Kaoshiung Municipal Government) dealing with the non-poisonous urban and industrial waste through reclamation of shore land in reinforcing a sense of coastal protection and land development in Tai-Lin-Pu coastal area, southern Taiwan.

Through a series of experimental studies, we found that substitutes of coarse aggregate with a broad spectrum of integrating slag powder, fly ash, and cementitious material can be obtained with a benefit up to 80% saving of cement. the integrated aggregates from the non-poisonous industrial wastes were subsequently made into armour units and used in the field tests at Tai-Lin-Pu coastal area, where the shorelines are seriously eroded. After being subjected to several severe typhoon advents, the results showed that the waste-made units used as the protection breakwater, together with construction wastes and excavated soil as the filling material, prove to be an effective practice in utilizing recycled urban waste to reclaim erosive shore lands. Moreover, this study also demonstrates that through detailed analysis of the waste characteristics, scrap material could be turned into valuable construction aggregates, and highlights the value of non-poisonous urban and industrial waste as a alternative resource for the shore protection engineering.     

Volume and financial value of species traded in the medicinal plant markets of Gauteng,South Africa

The demand for traditional medicinal plants and products in South Africa has created an extensive cross-border industry involving thousands of harvesters and traders. The market values of individual taxa vary considerably. Pricing structures fluctuate between markets and over time as the cost of harvesting species varies depending on a gatherer's access to the resources and the proximity of markets to the harvesting sites. This paper estimates trade values, describes the prices paid for 22 plant resources, investigates pricing structures relative to the mass/volume sold and the factors that influence the market price for plants. There is an inverse and disproportionate relationship between the price per kilogram (R/kg) and mass of the product sold. The smaller the quantity sold, the higher the R/kg sale values are relative to sales of larger quantities. This relationship is evident in different plant part types (e.g. bark and bulbs), species and markets (shops and street markets). Given the high mass sold relative to the price, bulbs, like bark, have the lowest R/kg values compared to other products like roots, fruits and leaves. The prices paid for heavier/denser species is thus disproportionate to the mass sold. If the relative values are used as an indicator of plant vulnerability (assuming high values indicate greater vulnerability), then bias is created in favour of 'lighter' and less dense plant parts typically sold in small quantities because of the nature of the plant part and the manner in which it is marketed and required by customers.     

Fishing quota markets

In 1986, New Zealand responded to the open-access problem by establishing the world's largest individual transferable quota (ITQ) system. Using a 15-year panel dataset from New Zealand that covers 33 species and more than 150 markets for fishing quotas, we assess trends in market activity, price dispersion, and the fundamentals determining quota prices. We find that market activity is sufficiently high in the economically important markets and that price dispersion has decreased. We also find evidence of economically rational behavior through the relationship between quota lease and sale prices and fishing output and input prices, ecological variability, and market interest rates. Controlling for these factors, our results show a greater increase in quota prices for fish stocks that faced significant reductions, consistent with increased profitability due to rationalization. Overall, this suggests that these markets are operating reasonably well, implying that ITQs can be effective instruments for efficient fisheries management.     

Green markets, eco-certification, and equilibrium fraud

Consumers voluntarily pay significant price premiums to acquire unobservable environmental attributes in green markets. This paper considers the performance of eco-certification policy under circumstances where consumers cannot discern environmental attributes in goods, but are able to form rational expectations regarding the extent of illicit activities in the green market. The main results are: (i) fraud is less prevalent in green markets when entry barriers limit the number of firms; (ii) conventional environmental policies on polluting techniques increase the incidence of fraud, and can even preclude the use of non-polluting techniques which would otherwise emerge in green markets; (iii) voluntary eco-certification policies can decrease fraud, increase output, and raise profits per firm; and (iv) in cases where the socially optimal resource allocation can be supported, the optimal policy involves negative unit certification fees, positive fixed certification fees and is revenue-generating for the certifying agent.     

Emissions Trading with Shares and Coupons when Control over Discharges Is Uncertain

Two important decisions in designing markets for tradable emissions permits are whether to allow banking of permits (coupons) and whether to allow trading in entitlements to future permits (shares). Banking is predicted to reduce price instability when firms trade in a reconciliation market after the quantity of emissions has been determined. Tradable shares are a common feature in proposals for emissions trading in Canada. We conduct a laboratory experiment to investigate how bankable coupons and tradable shares affect efficiency and prices under uncertainty. Cognitive demands on the subjects are reduced by computerized advice on the optimal allocation of coupons across periods and the implied marginal values of coupons and shares. Banking, share trading, and uncertainty conditions are introduced in a complete factorial design with three observations per cell. High efficiencies are observed across all treatments. Uncertainty in the control of emissions leads to substantial price instability when banking is not allowed. Banking virtually eliminates the instability, but reduces the efficiency of the market institution. Share trading reduces trading volumes, increases price stability, and improves efficiency.