Optimal user charges and cost recovery for roads in developing countries

The optimal charge for road use is equal to variable costs for road maintenance, together with the costs road users impose on other road users and on the rest of society. One persistent question raised about such charges is what impact they have on cost recovery. The theoretical literature argues that if there are constant returns to scale in road construction and in road use, the optimal user charge will recover the capital costs of the road network and the total expenditures on road maintenance. Empirical estimates for such a system of road user charges in Tunisia similarly suggest that they would generate twice the revenues currently spent on roads. The authors examine these issues from both theoretical and practical perspectives. They conclude that there are substantial economies of scale in both road construction and road use. Also, road maintenancecosts include a number of fixed costs that do not vary with traffic. Moreover, since roads cannot be smoothly adjusted to traffic, marginal costs for the entire road network are significantly lower than average costs in most developing countries, unless capacity is artificially constrained by environmental or other constraints. Under these conditions, optimal user charges result in a substantial financial deficit. The authors also address the question of how this deficit should be financed.Roads&Highways,Economic Theory&Research,Water Supply and Sanitation Finance,Airports and Air Services,Public Sector Economics&Finance

Older consumers in Malaysia : spending pattern, leisure activities and consumption preferences

This paper brings consumption activities into the domain of active ageing by proposing that consumption process en­gages older people physically, socially, and emotionally in line with the concept of active ageing. In Malaysia as in else­where in Asia, the number of older adults is growing and the attractiveness of this market segment is expected to grow in the years to come since the newer cohorts of older consumers have higher levels of educational achievement and income, and adopt a lifestyle that is different from their parents. In spite of this, marketers have largely overlooked this market segment. The focus of this paper is on grocery shopping since older people spent a large proportion of expenses on food and beverages. The study also examined the evaluative criteria that older people used for making purchase decisions. Their sources of information for various products and services which aid them in information search are also covered in the study. This paper also highlights leisure activity participation and media habits of these older consumers. Household survey which covered Peninsula Malaysia was conducted in urban and rural areas. Data from a total of 537 sets of responses were analysed. Urban respondents made up 68.3% of the sample with the remaining 31% from rural ar­eas. The mean age of respondents was 64 years (SD = 7.3). Male respondents made up 57% of the sample while females made up 43%. The Malays made up 56% of the sample, Chinese 29% and the Indians 12.1%. About 56% were retired or not employed, whereas about 225 were still gainfully employed either on a full-time or part-time basis. Another 22% were retired but continue to work on either a full-time or part-time basis. About 38% had monthly income of less than RM1500. Slightly more than one quarter had monthly income of between RM1500 to RM2499. Results showed that older adults commonly shopped at sundry shops, wet markets, supermarkets and weekend/night markets. They tended to shop alone or with their spouse. The most important reason for their choice of outlets for grocery shopping was ease of locating items or merchandise as reported by 83% of the respondents. The results showed that the most important criterion for purchase decision is quality followed by durability, safety features, comfort and price, while brand was the least important. Close to 100% had participated in at least a leisure activity. The common leisure activi­ties were: watching television, reading, gardening, and exercising. As for sources of information for various products and services, their reliance on their children was evident. They had confidence in interpersonal communication while their tendency to ignore advertised information was also apparent. From the results of this study, implications for marketers are many folds. Older adults are not passive consumers; they are active and discerning in knowing and expressing their preferences. Since the study suggests a two-step flow in communi­cation, i.e., older adults rely on their children for information marketers need to re-strategies their marketing communica­tions to reach this market segment. It would be wise to consider potential and profitable segments not just for their basic needs, but for other leisure related products or services since older people are active in leisure activity participation. An understanding of these older consumers could possibly make a difference, resulting in more accurate targeting and de­livery of services. 「马来西亚的银发市场：消费模式、休闲活动与消费偏好」 摘要 本论文透过论证消费过程令长者在生理上、社交上及情感上与积极老龄化的概念相配合，将消费行为带进积极老龄的领域。在马来西亚及其他亚洲国家，由于长者人口的增加，再加上新一批年长消费者有着较高的教育水平及收入，并过着与其上一辈不同的生活方式，我们将可预期长者市场板块的吸引力将逐渐增加。即便如此，商家大多忽略了此市场板块。 本文重心研究买菜的消费，因为长者支出大多在食物及饮品上。此研究探究长者在判断是否消费时的决定因素，包括商品或服务资讯及其来源。本论文也会聚焦在长者在消闲活动及媒体习惯的消费行为。 研究进行了涵盖整个马来西亚半岛城市及乡村地区的家庭住户调查，访问了537户；68.3%居于城市，31%居于乡郊；受访者平均年龄为64岁（SD=7.3）；男性受访者占57%，而女性则占43%；马来人占56%，华人占29%，而印度占12.1%；56%的受访者为已退休或非受雇，另外22%虽已退休但仍以全职或兼职的方式工作；约38%月入少于1500马币，只有仅多于四份一的受访住户的月入界符1500至2499马币。 研究结果显示，长者通常于杂货店、菜市场、超市及周末/夜市场消费。消费时他们多独自或偕同配偶前往。有83%的受访住户表示，令他们选择到某家商店消费的最主要因素是「容易寻找商品」。而决定是否购买某商品的最主要决定因素是该货品的质量，其次是耐用性、安全特点、舒适度和价钱，品牌则是最不重要。接近100%的受访者有参与至少一项消闲活动，而普遍的消闲活动包括：看电视、阅读、园艺和运动。在商品及服务的资讯来源，结果显示他们都依靠子女。研究结果亦明显显示长者在人际关系和沟通上有信心，并多无视广告资讯。 从研究结果我们可以为营商者带来多重的启示：长者并非被动的顾客；他们主动和精明，亦会表达他们的偏好。由于此研究提出两步的沟通流程，亦即：因为长者依靠子女提供资讯，商家宜重新制定他们的销售沟通方式以接触该消费群。营商者不单要考虑此消费群的基本需要的潜在可盈的市场，由于长者活跃于参与消闲活动，商家亦需要注重其他与消闲有关的商品和服务。理解长者消费群能带来转变，使市场提供的商品和服务更适切到位

Phonon scattering mechanisms in suspended nanostructures from 4 to 40 K

We have developed specially designed semiconductor devices for the measurement of thermal conductance in suspended nanostructures. By means of a novel subtractive comparison, we are able to deduce the phonon thermal conductance of individual nanoscale beams of different geometry and dopant profiles. The separate roles of important phonon scattering mechanisms are analyzed and a quantitative estimation of their respective scattering rates is obtained using the Callaway model. Diffuse surface scattering proves to be particularly important in the temperature range from 4 to 40 K. The rates of other scattering mechanisms, arising from phonon-phonon, phonon-electron, and phonon-point defect interactions, also appear to be significantly higher in nanostructures than in bulk samples

Causation and Responsibility: the Compensation Principle from Grotius to Calabresi

Calabresi often lamented that insufficient consideration had been given in the legal and economic literature to the idea of distributing an accident loss among a faultless tortfeasor and an innocent victim on the basis of the relative causal contribution of the parties to the loss. This criterion of apportionment of liability, which Calabresi calls comparative causation, is the object of this paper. We present a brief intellectual history of the principle of comparative causation, and provide a positive economic model that explains the rise and fall of this criterion of liability in historical and contemporary societies. In order to identify the structural features of this standard, we consider how a rule of comparative causation would perform in the absence of other liability rules, when applied as a general and sole basis of liability. The positive economic model of comparative causation brings to light some interesting features of the rule, but also unveils the limits of such criterion of liability with respect to the induced activity and care levels. The paper then extends the economic model to consider the workings of the comparative causation rule in conjunction with negligence rules. The combined application of the comparative causation and negligence rules induces the parties to minimize their expected liability by moderating their activity level: a combination of incentives that no known liability rule provides

Older consumers in Malaysia

The main objective of this study was to understand the concerns and problems faced by older people in an industrializing middle-income country, Malaysia, in their process of acquiring products to meet their everyday needs. Respondents aged 55 and over were interviewed in eight states throughout Peninsular Malaysia providing 1356 usable questionnaires; two-thirds from urban and one-third from rural areas. Education, health status, and life satisfaction were recorded. Service patronage behavior was examined for four main categories of commonly-sought consumer goods: groceries, health supplements, apparel, eating outlets, plus selected services (public transport, vacation packages and financial services). The findings showed that older adults in Malaysia are rather discerning consumers. Many respondents are price conscious and have developed consumer attitudes with regard to attitude of staff and assistance rendered. Many display a good ability to discriminate and to select, especially on the basis of price and durability of products and many appear to be acting as effectively as consumers in any other age group

Nanoscale, Phonon-Coupled Calorimetry with Sub-Attojoule/Kelvin Resolution

We have developed an ultrasensitive nanoscale calorimeter that enables heat capacity measurements upon minute, externally affixed (phonon-coupled) samples at low temperatures. For a 5 s measurement at 2 K, we demonstrate an unprecedented resolution of ΔC ~ 0.5 aJ/K (~36 000 k_B). This sensitivity is sufficient to enable heat capacity measurements upon zeptomole-scale samples or upon adsorbates with sub-monolayer coverage across the minute cross sections of these devices. We describe the fabrication and operation of these devices and demonstrate their sensitivity by measuring an adsorbed ^4He film with optimum resolution of ~3 × 10^(-5) monolayers upon an active surface area of only ~1.2 × 10^(-9) m^2