Your call: eBay and demand for the iPhone 4

The iPhone 4 was introduced into the UK market on 24th June 2010 to significant consumer interest. This clearly exceeded supply through conventional channels, since there was very extensive activity in terms of bidding on eBay auctions for the product. We monitored all eBay transactions on the iPhone 4 for six weeks from introduction, with total transactions amounting to around £1.5m. We analyse determinants of the winning bid in terms of characteristics of the phone, the seller and the buyer. Our most notable and novel finding relative to previous studies is a very significant premium over list price being paid in almost all cases, with positive uplift factors including whether the phone was unlocked and whether it could be sold overseas. Demand fell over time, as evidenced by lower achieved prices, but the fall in price was relatively modest. A significant premium of 32GB over 16GB versions is revealed.eBay auctions ; demand revelation ; auctions ; bidding ; short supply ; versioning JEL Classification: D44 ; L81 ; D12 ; L63

Crime and Drugs : An Economic Approach

We present a model which ties together rational drug consumption, taxation, crime and other drug-related externalities. Drug control policy is addressed using an optimal tax framework. Consumption, possession and production of a drug may be prohibited, legalized or decriminalized. In all regimes illicit production of a drug may take place and drug-related crime occurs. We show that illicit drug production, the price elasticity of demand for a drug, the addictive nature of a drug, the effectiveness of drug enforcement strategies, and income distribution all influence optimal (second best) policy. Prohibition is contrasted with decriminalization and legalization, and where legalization yields a higher welfare than prohibition we show that this can be associated with greater drug-related crime and more drug addiction. The model is discussed in the context of US National Drug Control Strategy.Crime ; decriminalization ; drugs ; externalities ; legalization ; optimal tax ; prohibition

Potential economic gains from using forage legumes in organic livestock systems in northern Europe

This report was presented at the UK Organic Research 2002 Conference of the Colloquium of Organic Researchers (COR). Forage legumes, with their ability to fix nitrogen biologically, seem especially attractive for organic livestock production. In an attempt to assess their true potential, this study draws on a four-year trial conducted at 12 sites in northern Europe with four different forage legumes. One third of the sites were managed as organic systems, with the harvested forage being fed as silage to dairy cows. Based on the trial results, an economic assessment has been made of the potential of forage legumes to improve the competitive edge of organic dairy systems, relative to conventional grass-based ones. Although the results suggest that the organic milk price premium plays a major role in determining the comparative profitability of organic dairy systems, the use of forage legumes also gives a significant cost advantage to organic production

A framework for assessing crop production from rotations

This report was presented at the UK Organic Research 2002 Conference of the Colloquium of Organic Researchers (COR). Organic farming systems rely on the management of biological cycles for the provision of nutrients, which are crucial to maximising the production from the system. Rotations based on the use of grass-legume leys are central to the concept of organic farming systems, because they have the potential to support both animal production, and a subsequent, exploitative, arable cropping phase. A major challenge in organic farming is managing the supply of nitrogen, since it has a key role in governing both productivity and environmental impact. Hence, within a rotational system, there is a need to understand the complex interactions that are occurring between crop species and management, livestock production system and the impact of soil and climate on these processes. To understand these interactions, a framework is being developed for rotational farming systems that describes the soil nitrogen, crop growth and livestock production. The framework must address questions that are relevant to researchers and extensions workers. Typical questions relate to the management of nutrients in the short and long-term. Additionally, there are concerns over the impact of weeds, pests and diseases on productivity, as well as the impact of adopting new strategies or crops on the farming system

Your call : eBay and demand for the iPhone 4

The iPhone 4 was introduced into the UK market on 24th June 2010 to significant consumer interest. This clearly exceeded supply through conventional channels, since there was very extensive activity in terms of bidding on eBay auctions for the product. We monitored all eBay transactions on the iPhone 4 for six weeks from introduction, with total transactions amounting to around £1.5m. We analyse determinants of the winning bid in terms of characteristics of the phone, the seller and the buyer. Our most notable and novel finding relative to previous studies is a very significant premium over list price being paid in almost all cases, with positive uplift factors including whether the phone was unlocked and whether it could be sold overseas. Demand fell over time, as evidenced by lower achieved prices, but the fall in price was relatively modest. A significant premium of 32GB over 16GB versions is revealed

Crime and drugs: an economic approach

We present a model which ties together rational drug consumption, taxation, crime and other drug-related externalities. Drug control policy is addressed using an optimal tax framework. Consumption, possession and production of a drug may be prohibited, legalized or decriminalized. In all regimes illicit production of a drug may take place and drug-related crime occurs. We show that illicit drug production, the price elasticity of demand for a drug, the addictive nature of a drug, the effectiveness of drug enforcement strategies, and income distribution all influence optimal (second best) policy. Prohibition is contrasted with decriminalization and legalization, and where legalization yields a higher welfare than prohibition we show that this can be associated with greater drug-related crime and more drug addiction. The model is discussed in the context of US National Drug Control Strategy

Spelling Instruction in the Primary Grades: Teachers’ Beliefs, Practices, and Concerns

This study examined Canadian teachers’ beliefs, practices and concerns about spelling instruction in the primary grades. Data from surveys (n = 56) indicated that most teachers believe that spelling is important and plan for spelling instruction. For most teachers, the spelling words and activities used, and the instructional resources they chose, reflected an attempt to incorporate both holistic and traditional approaches to instruction. Teachers reported that substantial numbers of children experience difficulty with spelling. They suggested that greater emphasis be placed on defining spelling outcomes in the curriculum, as well as on teacher education and resources for teaching spelling to diverse learners

E-cigarettes : the extent and impact of complementary dual-use

The highly controversial e-cigarette industry has generated considerable policy debate and mixed regulatory responses worldwide. Surprisingly, an issue that has been largely ignored is the categorisation of e-cigarettes as substitutes or (dynamic) complements for conventional smoking. We conduct an online survey of US participants finding that 37% of e-cigarette users view them primarily as complementary. We use this result along-side publicly available data to calibrate a cost-benefit analysis, estimating that complementarity reduces the potential costsavings of e-cigarettes by as much as 57% (or $3.3-4.9bn p.a.) relative to case with zero complementarity

Curious Replay for Model-based Adaptation

Agents must be able to adapt quickly as an environment changes. We find that existing model-based reinforcement learning agents are unable to do this well, in part because of how they use past experiences to train their world model. Here, we present Curious Replay -- a form of prioritized experience replay tailored to model-based agents through use of a curiosity-based priority signal. Agents using Curious Replay exhibit improved performance in an exploration paradigm inspired by animal behavior and on the Crafter benchmark. DreamerV3 with Curious Replay surpasses state-of-the-art performance on Crafter, achieving a mean score of 19.4 that substantially improves on the previous high score of 14.5 by DreamerV3 with uniform replay, while also maintaining similar performance on the Deepmind Control Suite. Code for Curious Replay is available at https://github.com/AutonomousAgentsLab/curiousreplayComment: Accepted at ICML 2023. Website at https://sites.google.com/view/curious-repla