Rationing can backfire : the day without a car in Mexico City

In November 1989, Mexico City's administration imposed a regulation banning each car from driving on a specific day of the week. The regulation has been both popular and controversial. Some feel that it is a reasonable concession aimed at alleviating congestion and pollution problems. Others feel it is both inefficient and unfair: inefficient in the way most rationing systems are inefficent, and unfair in that it is costly to some and easily avoided or accommodated by others. Some feel that it may also be so inefficient that it is counterproductive. The authors found evidence to support that view. Many households bought an additional car to get additional driving permits, and the amount of driving increased. Greater use of old cars and increased weekend driving may have contributed to the disappointing results of Mexico's one-day ban on driving: high welfare costs and none of the intended benefits.Roads&Highways,Economic Theory&Research,Environmental Economics&Policies,Financial Crisis Management&Restructuring,Country Strategy&Performance,Economic Theory&Research,Environmental Economics&Policies,Roads&Highways,Financial Crisis Management&Restructuring,Transport and Environment

Foreign aid's impact on public spending

Using a model of aid fungibility, the authors examine the relationship between foreign aid and public spending. Based on a panel of cross-country and time-series data, their results show that roughly 75 cents of every dollar given in net development assistance goes to current spending and 25 cents to capital spending in the recipient countries. But concessionary loans - a component of development assistance - stimulate far more government spending. Their results also show that aid increases both public and private investment. To test aid fungibility across both public spending categories, they use a newly constructed data series on the net disbursement of concessionary loans. They find that concessionary loans given to the transport and communication sector are fully nonfungible. But loans to the energy sector are converted into fungible monies and part of the funds leak into transport and communications. Loans to agriculture and education are also fungible. There is no evidence of concessionary funds being diverted for military purposes. Their results show that total public spending in the health sector has no impact on reducing infant mortality, but concessionary loans to the health sector do. This finding leads the authors to conclude that linking foreign aid to an agreed-upon public spending program in areas critical to development might be an effective way to transfer resources to developing countries.Decentralization,Gender and Development,Development Economics&Aid Effectiveness,Public Sector Economics&Finance,Economic Theory&Research,Inequality,Development Economics&Aid Effectiveness,Public Sector Economics&Finance,National Governance,Economic Stabilization

Is demand for polluting goods manageable? an econometric study of car ownership and use in Mexico

Charging for social marginal costs is efficient regardless of price elasticities, but the importance of getting prices"right"is greater the more manageable, or elastic, the demand. In efficient pollution control programs, options to make cars cleaner are combined optimally with demand conservation. The roles played by"cleaner cars"as compared with"fewer trips"are determined by empirical parameters: cheap, clean technologies would imply a great role for cleaner cars, while high demand elasticities lead to a greater role for demand reduction. In seminal research, evisence was found to support the hypothesis that demand for commodities such as gasoline should have lower price elasticities and higher income elasticities in developing than in industrial countries. The authors estimate a model of gasoline demand and car ownership in Mexico, using a panel of annual observations by state. Key features they introduce are instrumental variables on different data and the treatment of (1) possible dynamics, (2) measurement errors in the data, and (3) unobserved characteristics in individual states. They use tests of serial correlation in the residuals to model the dynamics properly. The resulting model is one of almost immediate adjustment, with a short-term price elasticity for gasoline close to the long-term estimate of -0.8. The model displays elasticities that are lower (for income) and higher (for price) than those hypothesized, and are within the range of elasticities found in industrial countries. Byproducts of the model: The elasticity of car purchases with respect to gasoline prices is positive. Scrappage decisions are affected by income and by car and gasoline prices. And these elasticities are not significantly different in the richer states. For policy purposes, these findings do not support"elasticity pessimism"The use of car services is sensitive to pricing, which suggests that consumers, for some of their demand, have reasonably good alternatives to car services. Consideration of external costs - such as accidents, congestion, air pollution, and road damage - thus involve considerable demand conservation.Inequality,Transport and Environment,Energy and Environment,Economic Theory&Research,Environmental Economics&Policies

Volume CXXIII, Number 22, April 28, 2006

WOS: 000291223700026This study aims to reveal to what extent Turkish chemistry teachers use laboratorys effectively and their perceptions on laboratory applications and the factors related to laboratory applications. In this cross-sectional survey, 408 chemistry teachers from the secondary schools in Izmir were given "Teacher Demographic form", "The Scale of Chemistry teachers' perceptions on Laboratory Applications" and "The Questionnaire for the factors effecting Laboratory Applications". The findings revealed that the teachers' perceptions on laboratory applications significantly vary according to their self-efficacy beliefs in laboratory applications, the type of school they graduated, the type of the school they are working at, their experience in teaching, their schools' physical conditions and assesment-evaluation techniques and chemistry program. The type of the experiment they use and the type of their schools are significantly correlated. However, their experiences in teaching, the type of school they graduated, the type of experiment they use are significantly uncorrelated. The teachers from Anatolian high schools mostly choose open-ended experiments while the others form vocational and state high schools choose closed end experiments. It is quite remarkable that all teachers in the survey prefer hypothesis-based experiments

Multicriteria sustainability evaluation of transport networks for selected European countries

As an essential economic activity, transportation has complex interactions with the environment and society. Since the concept of sustainable development has become one of the top priorities for nations, there has been a growing interest in evaluating the performance of transport systems with respect to sustainability issues. The main purpose of this study is to introduce a decision making framework to assess the sustainability of the transport networks in a multidimensional setting and a technique to identify non-compromise alternatives. We also propose an elucidation technique to identify according to which criteria a system needs to be improved and how much improvement is required to attain a certain level of sustainability. The proposed methods are applied to a set of selected European countries within a case study

Spatial and temporal variation in the distribution and abundance of Synechococcus spp., picoeukaryotes, nanoeukaryotes and Chlorophyll-a in the Eastern Black Sea

The abundance and distribution of Synechococcus spp., picoeukaryotes, nanoeukaryotes, and chlorophyll-a, were studied through the water column (from 0 – 100 m depth) during four different seasons along the Eastern Black Sea coast. Based on annual average values, Synechococcus spp. were numerically dominant with an annual average of 3.40×104 cells mL-1, ranging between 0.51 and 9.93×104 cells mL-1, followed by picoeukaryotes with an annual average of 0.79×103 cells mL-1, ranging from 0.05 to 3.93×103 cells mL-1. The nanoeukaryotes were the least abundant group in the region, with an annual average of 3.26×102 cells mL-1 ranging between 0.12 and 17.98×102 cells mL-1. The minimum and maximum values of Synechococcus spp. and picoeukaryotes were found at stations from Fatsaand Arhavi, while nanoeukaryotes had their minimum-maximum abundance at stations from Yomraand Ordu. Overall, the Synechococcus spp. seasonal cycle exhibited a bimodal distribution, with one peak in summer and the other in autumn. In contrast, picoeukaryote and nanoeukaryote seasonal cycles had unimodal distributions, with peaks during winter. The abundance of Synechococcus spp. was significantly negatively correlated with depth during winter, while picoeukaryotes tended to notably correlate with depth during autumn and winter (p < 0.05). Contrary, the abundance of nanoeukaryotes was considerably negatively correlated with depth in all seasons. The chlorophyll-a showed a striking negative correlation with depth during spring and autumn. There were particularly positive correlations among Synechococcus spp., picoeukaryotes, nanoeukaryotes and chlorophyll-a, implying their coexistence. However, the picoeukaryotes were significantly negatively-correlated with nanoeukaryotes

Purification of olive mill waste: a circular economy model for the Mediterranean region

When olive mill wastewater is given directly to nature without being treated, natural waters become coloured, aquatic life is adversely affected, surface and underground waters are polluted, bad odours occur, and soil quality deteriorates. For these reasons, waste water is not allowed to be poured into soil and water without being discharged. This problem has become a problem that needs to be solved for the Mediterranean countries. With this study, acid cracking and chemical treatability studies achieved the conversion of the physicochemical pretreatment process of olive black water to an automation system. With the applied processes, removal efficiencies of 85% for Chemical Oxygen Demand, 99% for suspended solids, 97% for oil grease and 92% for phenol were obtained. Since the mixing processes of the tanks in the chemical additions are long, the heating chamber in the acid cracking process is designed larger than the tanks. Thus, when there is a black water density in the system, the heating tank in this system can be used as a heating and resting tank in sudden densities in this system. This waste separation process includes producing raw materials, protecting natural resources, and increasing sustainability. In particular, separating the phenol material and making it usable have been essential gains