Noah's Ark is full of common species attractive to humans: The case of boid snakes in zoos

As the fate of endangered species may largely depend on human decisions, we analyzed the effect of species attractiveness to humans on conservation efforts devoted to captive breeding. Our respondents were asked to rank photographs of 56 species of boas and pythons according to perceived attractiveness. Surprisingly, attractiveness, body size and, marginally, also taxonomic uniqueness of the species were the only significant predictors of the size of zoo population. On the other hand, variables putatively associated with species rarity (inclusion in the Red List or protection by international law, geographic range size, and commercial price) had no effect. The range size was, however, positively correlated with attractiveness. As the perceived attractiveness affects at least some components of the conservation effort, it should not be further neglected but should be routinely included into conservation reasoning.     

Choke Price Bias in Choice Experiments

This paper reports on the results from a split sample choice experiment, where the effect of changing the maximum level of the cost attribute is investigated. The hypothesis was that changing the maximum price level would either give rise to an income effect or have no effect on consumers’ preferences. This was tested in the framework of a valuation study of different quality characteristics of minced pork. The data was analysed using a mixed logit error component model, which accounts for correlation in the unobserved part of the utility. Results suggest that the size of the maximum price level does matter, and that changing the maximum price level has a statistically significant effect on both the general preferences structure and the WTP estimates. Hence, researchers should be very careful when defining not only the range of the price attribute but also the maximum level of the price attribute.     

Strategic Pricing when Electricity is Storable

In this paper, we develop a simplified oligopoly model where hydro generators engage in dynamic Bertrand competition. Each player uses a Markov strategy based on the state of water reservoirs at the beginning of each period. The replenishing of water reservoirs, which affects generators' productive capacity, is governed by a stochastic process. Also, a price cap, i.e. a maximum bid allowed, is imposed on the market. We develop valuable insights for regulatory policy in predominantly hydro based electricity markets, including the effects of price caps, the efficiency of dispatch under strategic behavior and the likelihood of collusion.     

Global Ex-vessel Fish Price Database Revisited: A New Approach for Estimating ‘Missing’ Prices

The Global Ex-vessel Fish Price Database (Ex-vessel DB) reported in Sumaila et al. (J Bioecon 9(1):39–51, 2007) was the first comprehensive database that presents average annual ex-vessel prices for all commercially exploited marine fish stocks by nationality of the fishing fleet. It contained over 30,000 reported price items, covering the period from 1950 to the present, and supplemented missing prices with estimates based on prices from a different year, species group or fleet nationality. This paper describes a revised missing price estimation approach, focused on the computation of annual average international prices for each species group, adjusted to domestic prices using the real exchange rate based on national purchasing power parity. Key advantages of the new approach are that it allows a larger number of reported prices to be used in the price estimation, and accounts for relative price level differences that exist between countries. Our new approach should improve the estimates in regions where reported prices are scarce or non-existent by linking domestic prices to the trends in international prices. Our analysis, based on the revised ex-vessel price estimates (in real 2005 USD), shows that the global marine fisheries landings have generated total value of USD 4.2 trillion since 1950, including USD 100 billion in 2005.     

A study on financial opportunity costs of growing local varieties of sorghum in Ethiopia: Implications for on-farm conservation policy

The increasing interest in on-farm conservation is driven by its diverse attractive features — its participatory nature and its flexible and dynamic features; its capacity to maintain not only crop diversity but the knowledge that evolves with it; and the chance it offers to link conservation with utilization and farmers' livelihoods. To implement this strategy on a sustainable basis, policy incentives are crucial. This paper argues that opportunity costs farmers face have a role to play to design sound policy incentives. Taking sorghum as an example, opportunity costs have been examined in this paper using data collected from 198 farmers in Eastern Ethiopia. The average opportunity costs suggest the size of the required policy incentives and they are the basis to estimate the national conservation costs for on-farm conservation. The regression analysis shows that opportunity costs increase with access to output markets and extension, output price, access to input supply, experience in growing improved varieties, and the relative importance of the crop. On the contrary, plot quality, input price, and oxen ownership are reducing the opportunity costs. The paper then concludes outlining the policy implications of the empirical findings to incentive design for on-farm conservation.     

房价对城市全要素生产率的影响机制研究——基于Tobit模型实证分析

基于2008—2016年全国35个大中型城市的面板数据,利用Tobit模型和投入导向型的数据包络分析(DEA)方法探究城市房屋销售价格对城市全要素生产率的影响。研究发现：在整体维度城市房价与城市生产率呈现先增加后减少的倒U型曲线,且城市的房价水平超过了“房住不炒”的最高临界值,房价上升的抑制效应显著。房价对于不同人口规模城市的生产率影响具有异质性,在人口规模达到特大城市时,房价与城市生产率呈现倒U型特征,人口规模达到超大城市后,房价与城市生产率倒U型特征消失。不同类型城市房价与城市生产率之间的倒U型关系和城市的异质性特征表明,我国大中型城市应进行房价的“一城一策”精细化调节,“房住不炒”的政策定位具有坚实理论依据和现实必然。     

Emissions Pricing Policies and Business Cycles: Fixed vs. Variable Tax Regimes

As by-products, emissions follow economic fluctuations. Ignoring this fact in environmental policies can lead to unexpected emissions fluctuations and an increase in intervention costs. Using a real business cycle model, we compare two policies: a fixed tax policy where the price is constant over time and a variable tax regime where the tax rate is set at the beginning of each period. We find that while both programs result in lower emissions, a variable tax regime is preferable since first, it can ensure that the maximum welfare is always achieved, and second, it is more effective in stabilising emissions.     

Positioning and negotiations: The case of pharmaceutical pricing

We study a positioning game prior to negotiations where each party invests into influential activities in order to raise voter support for their preferred bargaining outcome. The case chosen for our analysis is a bilateral monopoly where a purchaser meets a pharmaceutical firm and where the two negotiate on the price of a new and innovative medicine. We identify factors that influence on the negotiated price such as treatment effects of the new and the existing drug, production costs of the new drug, the price of the existing drug, the marginal cost of public funds and patient group size. Furthermore, it is shown that the negotiated price, depending on the characteristics of a political cost function with regard to the influential activities, is influenced by the order of moves taken by the parties. Regardless of the strategic interrelationships between the two parties, likely positioning games to be played are those where one of the two negotiating parties acts as a leader while the rival acts as a follower.     

The Effect of Bidder Heterogeneity on Combinatorial Conservation Auction Designs

In an iterative combinatorial auction, bidders can submit bids on individual and/or on combinations of projects in a series of intermediate rounds, where bid prices are revised before a final allocation is made. The iterative format is useful for conservation service procurement as landholders can rely on market information revealed through the rounds to evaluate their choices of projects and bid prices. However, there is no single way of providing the market information. Different designs for generating price information have been proposed. Little is known about the performance of iterative combinatorial auction designs when heterogeneous bidders, with different cost structures, participate in an auction. Using an agent based model, we evaluate a selected set of designs under different bidder heterogeneity scenarios. We observe that higher degrees of heterogeneity lead to lower auction efficiency and that auction outcomes are highly sensitive to price feedback design choices.     

A Global Ex-vessel Fish Price Database: Construction and Applications

Synopsis We describe the first effort at creating a global ex-vessel fish price database, which is required for understanding the economic behavior of participants in the world’s fisheries. We demonstrate potential applications of the database by linking it to a spatially defined catch database, which makes it possible to attach landed values to species in both time and space. This is the first database available publicly where interested members of the public, researchers and managers can easily find and access ex-vessel prices of the world’s major commercial fish species. Preliminary results indicate that the average real price of a number of species have declined between 1950 and 2002. The estimated landed value of fish globally, in year 2000 dollars, was about US$24 billion in 1950. It increased steadily to about US$90 billion in the early 1970s, reached a peak of US$100 billion at the end of the 1980s, and declined to about US$80 billion in 2000. The top 15 fishing countries cumulatively account for 79% of total real landed value, with Japan leading, even though the value of its landings has been declining.      

Linear exchange economies with a continuum of agents

The purpose of this paper is to study how the equilibrium prices vary with respect to the initial endowments in a linear exchange economy with a continuum of agents. We first state the model and give conditions of an increasing strength for existence, uniqueness and continuity of equilibrium prices. Then, if we restrict ourselves to economies with essentially bounded initial endowments and if we assume that there is, from the point of view of preferences, only a finite number of types of agents, we show that, on an open dense subset of the space of initial endowments, the equilibrium price vector is an infinitely differentiable function of the initial endowments. The proof of this claim is based on a formula allowing to compute the equilibrium price vector around a so-called “regular” endowment where it is known.     

Price search and spatial competition

In this paper we study a model where two spatially scattered sellers face a population of consumers dispersed over a given geographical area; they have to incur a transaction cost to place their purchase order. Moreover these consumers have imperfect knowledge of prices, but obtain full information about prices at the first shop they solicit. We study price competition between these firms. The main outcomes of our analysis are as follows. First we show that whenever a price equilibrium exists for given locations of firms, it will necessarily display price dispersion. Second we study location configurations which ensure the existence of a price equilibrium. Furthermore we show that when it exists, a price equilibrium is unique. Finally we analyze firms revenues when merchants anticipate the consequences of their locational choice on subsequent price competition. Then we find that there is an incentive for a firm to get as close as possible to its competitor.     

Consumer confusion,obfuscation and price regulation

This paper studies firms’ obfuscation choices in a duopoly setting where two firms differ in their marginal costs of production. We show that the high‐cost firm chooses maximum obfuscation while the low‐cost firm chooses minimal (maximal) obfuscation if the cost advantage is large (small). We argue that in this setting there is a new role for price regulation as it leads to more transparent pricing. Moreover, a price cap benefits social welfare as it shifts production to the more efficient low‐cost firm.     

Quality competition,welfare, and regulation

In this paper, we study the supply of quality in imperfectly competitive markets, and explore the role of regulation in markets where firms may use both quality and price to compete for customers. In a model where firms first choose qualities and then prices, we find that quality decisions have strategic effects: firms react to quality disadvantages by price reductions. Because of this strategic effect, firms do not have the correct incentive to set socially efficient quality levels. Price and quality competition results in a socially suboptimal quality level. Efficiency can be restored by lump-sum transfers and price regulatory policies. Simple price regulation may result in lower price and higher quality.We thank Nicholas Economides, Randall Ellis, Thomas McGuire, Michael Riordan, and Monika Schnitzer for discussing various issues in this research with us. We are also grateful to a referee for helpful comments and suggestions. The first author acknowledges support from the Management Science Group, Department of Veterans Affairs at Bedford, Massachusetts. The ideas here do not represent those of the Department of Veterans Affairs.     

Uncertainty over future environmental taxes

Besides static efficiency properties, environmental policies should be evaluated in terms of their longer-run impacts on investment and technological change to reduce pollution and degradation of natural resources. Using a stochastic dynamic programming approach, this paper analyzes how uncertainty about a future environmental tax on a polluting input alters investment in resource conservation and how such investment affects future demand for the polluting input. The impact on investment depends crucially on price elasticities of demand and on the manner in which investment shifts and rotates the demand schedule for the polluting input in the future. The expectation of a higher tax does not necessarily create stronger incentives for investment in resource conservation. More uncertainty about future policies does encourage investment if it makes a firm more responsive to future price changes and discourages investment if it makes a firm less responsive to price changes.     

How to Get There From Here: Ecological and Economic Dynamics of Ecosystem Service Provision

Using a bioeconomic model of a coral reef-mangrove-seagrass system, we analyze the dynamic path of incentives to achieve an efficient transition to the steady state levels of fish biomass and mangrove habitat conservation. Our model nests different types of species habitat dependency and allows for changes in the extent of habitat to affect the growth rate and the long-run fish level. We solve the two-control, two-state non-linear optimal control problem numerically and compute the input efficiency frontier characterizing the tradeoff between mangrove habitat and fish population. After identifying the optimal locus on the frontier, we determine the optimal transition path to the frontier from a set of initial conditions to illustrate the necessary investments. Finally, we demonstrate how dynamic conservation incentives (payments for ecosystem services) for a particular habitat with multiple services are interdependent, change over time, and can be greater than contemporaneous fishing profits when the ecosystem is degraded.     

Dynamic and Comparative Static Analysis of Imperfectly Competitive International Fishery

A dynamic system for change of fish stock is formulated assuming that two asymmetric rival countries harvest fish from a common fishing ground and sell it in an imperfectly competitive market. The existence of a unique stable steady state is examined based on the dynamic system. Comparative static analysis is conducted in relation to changes in national fishing management policies to explore, among other things, rent-shifting from one country to another.     

Ecological and economic sustainability in fishery management: A multi-agent model for understanding competition and cooperation

Recent studies have shown that many marine ecosystems are experiencing an accelerating loss of population and biodiversity. It is apparent that there is a growing disparity between the available supply of fish and the desire of the growing world population to catch them. Although studies have begun to question the ecological sustainability of managed fishery systems, they often omit the corresponding effects on the economic sustainability of fishery industries. This is particularly important in rural coastal areas where the fishing industry is often a dominant employer. In this article, we analyze the interactions between economic and ecological dynamic systems using a multi-agent dynamic model of fishery management. Multiple agents (fishers) harvest multiple fish species and adapt the amount and allocation of their effort to their value functions, which are given as net profits of the fish harvest sold for a market price. This is largely unique in fishery models, since many econometric studies view fishers as represented by homogenous ‘average’ agents. We introduce and compare two different decision rules governing the behavior of fishers engaged in a competitive market. We demonstrate a situation where both behaviors lead to a decline of all fish stocks, as well as profits for most fishers. As an alternative, we introduce a cooperative approach in which fisheries jointly set sustainable limits for total harvest and effort that are then distributed to the fishers according to distribution rules. The simulation reveals that fish stocks and profits can stabilize at significantly higher levels in the cooperative case, leading to a continuous accumulation of capital for all fishers. This model demonstrates key aspects of overfishing conflicts that can be overcome through planned fishing quotas and cooperative market mechanisms. It also demonstrates a novel approach for simulating the dynamic behavior of heterogeneous fishers.     

Stock price synchronicity to oil shocks across quantiles: Evidence from Chinese oil firms

This paper investigates behaviour of stock price synchronicity to oil shocks across quantiles for Chinese oil firms. The spillover effects of the oil market on a firm are segregated into firm-specific and market-wide information. First, our results report a higher level of synchronicity by dynamic conditional correlations than by R-square since the former better captures dynamic linear dependence. Second, we find strong evidence of size effect. In particular, stock price synchronicity is generally higher in large-cap firms than in small-cap ones. Oil shocks affect synchronicity in the upper quantiles differently based on firm size. Third, we also find that synchronicity responds to oil shocks significantly in extreme low quantiles, implying that shocks in the oil market are transmitted to Chinese oil firms via firm-specific information. Finally, we determine that oil shocks have little or no immediate impact on stock price synchronicity; instead, cumulative lagged effect is evident. This evidence highlights the lagging effect of spillover of oil shocks on Chinese oil firms.     

Monopoly with local knowledge of demand function

In this note, we propose a model where a quantity setting monopolist has incomplete knowledge of the demand function. In each period, the firm sets the quantity produced observing only the selling price and the slope of the demand curve at that quantity. Given this information and through a learning process the firm estimates a linear subjective demand curve. We show that the steady states of the dynamic equation are critical points of the objective profit function. Moreover, results depend on convexity/concavity of the demand. When the demand function is convex and the objective profit function has a unique critical point: the steady state is a globally stable maximum; conversely when then steady state is not unique, local maximums are locally stable, while local minimums are locally unstable. On the other hand when the demand function is concave, the unique critical point is a maximum: there can be stability or instability of the critical point and period two cycles around it via a flip bifurcation. Moreover, through simulations we can observe that, with a mixed inverse demand function, there are different dynamic behaviors, from stability to chaos and that we have transition to complex dynamics via a sequence of period-doubling bifurcations. Finally, we show that the same results can be obtained if the monopolist is a price setter.