税收竞争对环境污染的影响及传导机制分析

在中国经济高增长的背后,环境污染问题愈发凸显,不利于经济的可持续增长。税收竞争是影响环境污染的主要因素之一,但是学术界研究税收竞争对环境污染的影响及其作用机制的较少。本文按照污染物属性将其划分为外溢性污染物和非外溢性污染物,通过构建一个包含生产者、消费者、地方政府及中央政府的一般均衡模型,刻画了在税收竞争的背景下,地方政府的税收征管效率对不同属性污染物的影响及其传导机制。结果发现当污染物具有外溢性属性时,税收征管效率对该地环境污染的影响通过改变本地及周边地区资本存量渠道实现;当污染物具有非外溢性属性时,降低税收征管效率通过增加该地区资本存量而提高了环境污染。文章首先使用随机前沿模型测算了2007—2014年中国28个省份企业所得税的税收征管效率,并将其作为税收竞争的衡量指标,然后运用系统GMM法证实了所提的假说。研究显示:地方政府的税收竞争增加了本地区的资本存量;税收竞争是将本地资本存量作为其推高外溢性污染物(二氧化硫)及非外溢性污染物(固体废弃物)排放量的一个主要渠道,邻近地区资本存量则是推高外溢性污染物(二氧化硫)的次要渠道。这意味着,要想改善环境质量,中央政府应规范地方政府的税收竞争行为,尽快建立一套科学、有效的绿色GDP评价体系;完善地方转移支付制度;应针对各个地区的污染及经济发展情况利用财政激励手段引入环保、绿色的资本项目;地方政府应减少不利于环境改善的地方财政支出,增加环保投入比重。     

Is the National Water Commission an appropriate institutional and governance structure to address the fundamental requirements of the water and irrigation industry in Australia?

The National Water Commission (NWC) and the $2 billion Australian Government Water Fund (the fund) has drawn attention to the need for innovative and adaptive practices for water use. The NWC and the fund, whilst a critical and catalytic step in the recognition of the current water situation in Australia, has thus far neglected to consider the systemic failures of the water, irrigation and related industries that led to this point. The underlying issue of the efficient allocation of water resources can be resolved by the harmonisation of competing demands (economic, social and environmental) and the establishment of governance structures to reduce institutional impediments. The linking of the fund to National Competition Council (NCC) payments is an important consideration in this process. This paper will argue that governance reform and institutional (re)alignment to remedy the impediments to the efficient allocation of water resources needs to be embedded in and linked to national competition policy principles. This paper will consider the NWC in this context with the aim of informing future policy to consider the systemic failures of the water industry and to forge institutional change for the more effective allocation of water.     

Oviposition site guarding by male walnut flies and its possible consequences for mating success

Field studies showed that male Rhagoletis juglandis and R. boycei flies guard egg-laying punctures (and the eggs within) on host walnut (Juglans major) fruit and defend those sites from conspecific and heterospecific males. In field experiments with artificially punctured fruit,as well as field observations on unmanipulated fruit, males were consistently more likely to be sighted and stayed longer on damaged fruit than on undamaged fruit. On artificially punctured fruit, they consistently spent more time in the vicinity of a puncture than expected by chance alone. Males together on damaged fruit were more likely to engage in contests over those fruit than males together on undamaged fruit. Copulations were consistently more frequent for either species on damaged than undamaged fruit, both in observations of unmanipulated fruit and in artificial puncture experiments. Analyses which controlled for the longer male residence time on damaged fruit suggested strongly that copulations were consistently achieved at higher per capita rates on damaged than on undamaged fruit, indicating that puncture-guarding functions to increase access to females. An exception to the pattern in male mating success was noted at a site where both species used host fruit on the same trees. In this case, R. juglandis males were only slightly more common on punctured fruit than on control fruit and male success in copulation did not differ significantly between the two types of fruit. This anomalous result was apparently due to an almost absolute advantage enjoyed by R. boycei males in on-fruit contests with R. juglandis males. A likely basis for improvements in mating success associated with puncture guarding was a propensity for females to deposit eggs into existing punctures. Both in observations of unmanipulated fruit and in artificial puncture experiments, females consistently attempted oviposition more often in damaged than undamaged fruit. In artificial puncture experiments, both species at both sites deposited most clutches in damaged fruit. Mating generally took place as females initiated oviposition. The possible functions of puncture use by females as well as alternative functions of puncture guarding by males are discussed.     

A review of recent developments in lake modelling

This paper reviews the lake models published the last five years, mainly in Ecological Modelling. The review shows that structurally dynamic modelling and coupling between hydrodynamic and ecological models are applied increasingly. A number of processes that have not been included in lake models before have been proposed. It has been shown that these additional processes in specific case studies are significant, for instance the competition between phytoplankton and macrophytes or cyanobacteria growth and growth of mussels. It is recommended to study these models for the development of models for case studies where these processes are relevant.     

Reducing over-reporting of deterministic co-occurrence patterns in biotic communities

Null models of species co-occurrence are widely used to infer the existence of various ecological processes. Here we investigate the susceptibility of the most commonly used of these models (the C-score in conjunction with the sequential swap algorithm) to type 1 and type 2 errors. To do this we use simulated datasets with a range of numbers of sites, species and coefficients of variation (CV) in species abundance. We find that this model is particularly susceptible to type 1 errors when applied to large matrices and those with low CV in species abundance. As expected, type 2 error rates decrease with increasing numbers of sites and species, although they increase with increasing CV in species abundance. Despite this, power remains acceptable over a wide range of parameter combinations. The susceptibility of this analytical method to type 1 errors indicates that many previous studies may have incorrectly reported the existence of deterministic patterns of species co-occurrence. We demonstrate that in order to overcome the problem of high type 1 error rates, the number of swaps used to generate null distributions for smaller matrices needs to be increased to over 50,000 swaps (well beyond the 5000 commonly used in published analyses and the 30,000 suggested by Lehsten and Harmand, 2006). We also show that this approach reduces type 1 error rates in real datasets. However, even using this solution, larger datasets still suffer from high type 1 error rates. Such datasets therefore require the use of very large numbers of swaps, which calls for improvements in the most commonly used software. In general, users of this powerful analytical method must be aware that they need surprisingly large numbers of swaps to obtain unbiased estimates of structuring in biotic communities.     

Private and public interests in water and energy

Based on empirical evidence from developed, transition and developing countries, the article looks at how the introduction of private operators’ interests into the water supply/sanitation and energy sectors may conflict with public interests in socio‐economic, environmental and political dimensions. Case studies are used to illustrate the dynamics of these interactions, covering phenomena such as unsolicited proposals, misrepresentation and corruption; the exploitation of established positions by taking advantage of asymmetry of information and negotiating capacity in relation to public authorities; and exit from contracts or concessions when acceptable profitability cannot be attained. This experience indicates that the introduction of private companies into these sectors creates the permanent possibility of conflict between private and public interests. The services are too vital both socially and economically to rely on corporate self‐regulation, and countries lack effective capacity to regulate such corporations. The authors conclude that policies relying on corporate activity in these sectors are unnecessarily risky, and that policy development should focus on building strong public sector institutions to provide these services.     

Secondary succession on a high salt marsh at different grazing intensities

Succession occurs on a large part of German salt marshes following abandonment or reduction of grazing. Its speed and effect on the biodiversity of salt marshes has been discussed in the literature. Permanent plot studies show site-dependent differences in successional outcome. If grazing is to be continued, there is uncertainty about the stocking rates that are optimal for the conservation of plant diversity. We present an eight year permanent plot study with different grazing treatments on a high salt marsh at the marsh island of Hallig Langeness, Germany, which is enclosed by a summer dike. The study site is owned by WWF. Successional outcomes on the permanent plots depend on grazing intensity and depth of the groundwater table which is correlated with soil salinity. Intermediate stocking rates support a mixture of halophytes and glycophytes, the relative proportion of which depends on the depth of the groundwater table. Cattle grazing at stocking rates of 0.6 livestock units per ha were found to be optimal for plant diversity conservation. At sites with deeper groundwater tables and no grazing, dominantElymus spp. stands develop and diversity is strongly reduced. If the groundwater table is high, succession following grazing abandonment is retarded and small halophytes prevail.     

Examining the colonization process of exotic species varying in competitive abilities using a cellular automaton model

Current threats of invasive species have significant implications for ecological systems. Given their potential impacts, invasive species have been the subject of extensive empirical and theoretical studies. However, these studies have tended to focus on species that produce highly visible ecological and economic impacts. In our study, we take a step back from focusing on these high-impact invasive species, and examine the general colonization (invasion) process of exotic species that have various “competitive abilities” against the native species. Using a two-species cellular automaton model, we demonstrate that: (1) a threshold level of competitive ability is required for the exotic species to successfully establish in a new landscape and (2) an exotic species with superior competitive ability does not necessarily become dominant in a landscape (alternatively, a species that has inferior competitive ability may successfully colonize a new system). Our findings have significant implications for the study of species invasions and also provide clues to how species assemble in ecological communities.     

Do newborn domestic rabbits Oryctolagus cuniculus compete for thermally advantageous positions in the litter huddle?

Competition among mammalian siblings for scarce resources can be severe. Whereas research to date has focused on competition for the mother’s milk, the young of many (particularly altricial) species might also be expected to compete for thermally favorable positions within the nest, den, or litter huddle. We investigated this in newborn pups of the European rabbit Oryctolagus cuniculus, a species in which the altricial young are not brooded by the mother, and in which competition for milk is severe. In eight unculled litters (N = 86 pups) of a domestic chinchilla strain, we calculated huddling indexes for individual pups on postnatal days 2–5 as a measure of the degree of insulation they received from littermates. Pups maintained almost constant physical contact with the litter huddle. They performed brief but frequent rooting and climbing behaviors, which usually improved their huddling index, interspersed with longer periods of quiescence during which their huddling index declined. As expected, we found a significant positive relation between pups’ mean huddling index and body temperature. Unexpectedly, however, we did not find a relation between huddling index and pups’ birth weight, survival, milk intake, or efficiency of converting milk to body mass. We conclude that rather than competing for thermally advantageous positions within the huddle newborn rabbits share out thermally advantageous positions as they move in a continual dynamic flow through it. Thus, in newborn rabbits, competition for the mother’s milk exists alongside mutual “cooperative” benefits of littermate presence. This contribution is part of the special issue “Sibling competition and cooperation in mammals” (guest editors: Robyn Hudson and Fritz Trillmich).