Induced innovation and land degradation: Results from a bioeconomic model of a village in West Africa

This paper introduces a modeling method which simulates a village's response to population and market pressure. The method combines a recursive and dynamic linear programming model with a biophysical model of soil condition and plant growth that predicts yields and land degradation for different type of land, land use and cropping patterns. The linear programming model simulates farmers' plans aggregated at the village level under constraints of risk aversion, food consumption, land area, soil fertility, soil depth, labor and cash availability. Detailed agroecological factors determine Ihe main processes of land degradation. A large number of technological alternatives, representing different degrees of labor and/or land-saving techniques available in the study areas, are introduced, taking into account their respective constraints, costs and advantages. The method has been calibrated for a village located in the sub-humid region of Burkina Faso. Several simulations are carried out to the Year 2030. The results show that population pressure leads to intensification and investment in land conservation practices out not necessarily to better farm incomes. Increasing market opportunities can play a more positive role in boosting productivity, but for the next decades the best way to increase production per farmer is to let farmers migrate from the high-population-density areas to the low-population-density areas because, under the current economic conditions of most Sahelian countries, intensification per hectare is stil more expensive than the fallow system.     

基于计算机数据分析的品牌价格平衡模型

随着计算机网络与通信技术的发展,信息技术在市场预测模型中的应用越来越广泛。基于计算机数据分析的品牌价格平衡模型（Brand Price Trade-Off）,成为国外目前最为成功的一种在模拟竞争环境下测试品牌价格策略的高级研究技术。     

Your Call: eBay and Demand for the iPhone 4☆

The iPhone 4 was introduced into the UK market on 24^th June 2010 to significant consumer interest. Demand revealed itself exceeding supply through conventional channels, since there was very extensive activity in terms of bidding on eBay auctions for the product. We monitored all UK eBay transactions on the iPhone 4 for six weeks from introduction, with total transactions amounting to around £1.5m. We analyse determinants of winning bids 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.     

How does population density influence agricultural intensification and productivity? Evidence from Malawi

This article uses nationally representative household-level panel data from Malawi to estimate how rural population density impacts agricultural intensification and household well-being. We find that areas of higher population density are associated with smaller farm sizes, lower real agricultural wage rates, and higher real maize prices. Any input intensification that occurs seems to be going to increasing maize yields, as we find no evidence that increases in population density enable farmers to increase gross value of crop output per hectare. We also find evidence that households in more densely populated areas increasingly rely on off-farm income to earn a living, but there appears to be a rural population density threshold beyond which households can no longer increase off-farm income per capita.     

Control of SO2 emissions from power plants: A case of induced technological innovation in the U.S.

This paper investigates how the details of government actions induce innovation—the overlapping activities of invention, adoption and diffusion, and learning by doing—in “environmental technology,” products and processes that either control pollutant emissions or prevent emissions altogether. It applies multiple quantitative and qualitative measures of innovation to a case subject to several “technology-push” and “demand-pull” instruments: sulfur dioxide control technology for power plants. The study employs analyses of public R&D funding, patents, expert interviews, learning curves, conference proceedings, and experience curves. Results indicate that: regulation and the anticipation of regulation stimulate invention; technology-push instruments appear to be less effective at prompting invention than demand-pull instruments; and regulatory stringency focuses inventive activity along certain technology pathways. Increased diffusion of the technology results in significant and predictable operating cost reductions in existing systems, as well as notable efficiency improvements and capital cost reductions in new systems. Government plays an important role in fostering knowledge transfer via technical conferences, as well as affecting the pattern of collaborative relationships within the technical research community via regulatory changes that affect the market for the technology. Finally, the case provides little evidence for the claim that cap-and-trade instruments induce innovation more effectively than other instruments.     

Critical mass of users versus critical mass of services in a multiproduct information service system

In this paper we study the economic behaviour of the suppliers of a set of advanced telecommunications services with a joint adoption cost (common access facilities, learning process, etc.). In fixing the two-part tariffs for their services the suppliers have to share the burden of leaving to the users a surplus sufficient to cover the adoption cost. The lack of coordination in supplying a critical mass of services or in the pricing decisions has high changes to result in suboptimal or unviable diffusion of the new technology as a whole. We present a static optimization model of user behaviour, and derive access and usage demand with a two-part tariff and a joint adoption cost. We compare noncooperative and cooperative market equilibria in a duopoly with perfect information; finally we discuss the extension of our analysis to the case of imperfect information in a dynamic setting.     

The patterns of induced diffusion: Evidence from the international diffusion of wind energy

Recent years have seen growing academic interest in the concept of induced diffusion as efforts to address concerns about energy security and climate change have intensified. Research on induced diffusion explores whether policy tools or interventions can incentivise the diffusion of innovations. This body of literature has explored the effectiveness and efficiency of various policy interventions and as such has been mainly concerned with the determinants of diffusion. This paper is, by way of contrast, concerned with the patterns of diffusion when diffusion is induced. Drawing on the Bass and Davies models of innovation diffusion we develop a number of propositions that suggest that the patterns of diffusion are different when policy plays a role in the diffusion process. These propositions are then econometrically tested in the context of the international diffusion of wind energy in 25 OECD countries. We find that, as predicted, without effective and strong policy interventions, countries will have conventional logistic diffusion with very similar speeds of diffusion. However, as expected the patterns of diffusion take on a different functional form (Bass curve) when there is a strong policy inducement. We conclude by discussing the implications and limitations of these results and suggesting avenues for further research.     

财政奖励政策对农村金融机构信贷行为的影响——基于涉农贷款增量奖励政策的实证研究

涉农贷款增量奖励政策是将财政政策与信贷政策有机结合,发挥财政资金杠杆作用,促进金融资源优化配置,建立财政促进金融支农的一项重要举措.本文利用新疆70个县的涉农贷款、农户贷款、奖励资金数据,分别构造了自回归分布滞后（ADL）模型和面板数据（Panel Data）模型,并对财政奖励政策的金融机构信贷行为影响效应进行了检验,然后通过农村金融需求问卷调查结果对金融机构信贷行为的影响进行了进一步验证.结果表明：第一,财政奖励政策对县域金融机构涉农贷款和农户贷款的发放存在正向激励作用,但多个县域个体并未表现出显著的激励效应;第二,财政资金奖励政策对农户和农村企业的信贷需求满足度均有明显影响,但对农村信贷资金价格并未表现出显著的影响.     

我国旅行社从业人员总量需求趋势实证研究

随着旅游业在我国国民经济中地位的不断提高及旅游业的快速发展,旅游从业人员的数量也要不断增加,旅行社业作为旅游业的主要板块,其从业人员的数量及质量都将对其行业的发展产生重大影响。本文主要借助科学的方法,在占有大量资料的基础上,从实证的角度对我国旅行社未来几年的从业人员的总量进行了预测分析,以为相关部门及院校提供有益的参考。