Loanable Funds, Monitoring and Banking

This paper studies financial intermediation in a general equilibriumoverlapping generations model. Indivisible investment projects combine withinformational imperfections to create a (hidden action) moral hazard problemand introduce a role for third-party monitoring. Agency costs at theintermediary level are also considered. Under some conditions, monitors canbe viewed as banks facing a non-trivial portfolio diversification problem.Equilibria are derived in which a large nationwide bank coexists with anumber of community-regional banks, a structure of strong empiricalrelevance. Policies such as a mandatory reserve requirement are shown tohave substantial effects on the levels of investment in the economy.     

TRENDS IN RURAL WAGES,WEST JAVA, 1977–83

This paper examines monthly wage data collected by the Agro Economic Survey from seven villages in the Cimanuk River Basin of West Java, where data on agricultural and non-agricultural wages and prices of nine essential commodities were collected twice monthly between 1977 and 1983. Movements in money wages deflated by both the rice price and a weighted index of basic commodities are analysed in detail and differences between lowland and upland villages are discussed.     

Fermentative hydrogen production in a system using anaerobic digester sludge without heat treatment as a biomass source.

Hydrogen produced from anaerobic fermentation of organic matter is a sustainable energy source. Anaerobic hydrogen-producing systems have been typically seeded with heat-treated inocula to eliminate hydrogen-consuming methanogens. This can be both energy- and economically-intensive. In this work, operational parameters were modified to determine if operating a reactor at low pH (5.5) and low SRT (10 hours) would result in a hydrogen-producing system free of methanogens using anaerobic digester sludge with no heat treatment as an inoculum. Initially, the reactor exhibited a hydrogen productivity of approximately 7.9% when fed glucose. After purging was begun with 10% CO2/90% N2, the hydrogen productivity increased to > 20% for the first day. Hydrogenotrophic methanogens then established themselves in the reactor, reducing the hydrogen productivity in the second non-purged phase by 80%. The operational controls examined were not sufficient to eliminate hydrogen-consuming methanogens for longer than approximately one week, and thus further methods must be developed.     

PRODUCTIVITY GROWTH IN AGRICULTURE (REVISITED): A MEASUREMENT FRAMEWORK AND SOME EMPIRICAL RESULTS

This paper explores the methodology of sectoral productivity growth measurement within the framework of input-output analysis. A method which ensures that sectoral productivity growth rates are consistent with productivity growth rates for the economy as a whole (as well as allowing for external trade) is suggested. New estimates are presented on total factor productivity in UK agriculture using a Tornqvist index procedure. In addition, new estimates of agricultural labour productivity growth are presented, taking account not only of labour employed in agriculture but also of labour employed in ancillary industries on the supply side. The empirical results confirm that part of the labour previously employed on farms has shifted “upstream” to industries providing agriculture with fertilises, machinery and other inputs.     

Retention of Escherichia coli in municipal sewage by means of planted soil filters in two-stage pilot plant systems.

Different types of constructed wetlands in a pilot-plant system were fed with identical municipal waste water to compare the sanitisation process in two-stage systems. With combinations of a vertical and a horizontal flow filter an E. coli reduction of 5 log10 with an E. coli influent concentration of 10(7) MPN/100 ml was achieved. Using different filter materials in each stage the total performance of the two-stage system was independent from the sequence of these materials. However, using coarser filter material in the first stage makes the filter less prone to clogging and is thus the preferential option with regard to operational reliability.     

Application of a multi-channel system for continuous monitoring and an early warning system.

A multi-channel continuous toxicity monitoring system developed in our laboratory, based on two-stage mini-bioreactors, was successfully implemented in the form of computer-based data acquisition. The multi-channel system consists of a series of a two-stage minibioreactor systems connected by a fiber optic probe to a luminometer, and uses genetically engineered bioluminescent bacteria for the detection of the potential toxicity from the soluble chemicals. This system can be stably and continuously operated due to the separation of the culture reactor from the test reactor and accomplish easy and long-term monitoring without system shut down by abrupt inflows of severe polluting chemicals. Four different recombinant bioluminescent bacteria were used in different channels so that the modes of the samples toxicities can be reasonably identified and evaluated based upon the response signature of each channel. The bioluminescent signatures were delivered from four channels by switching one at once, while the data is automatically logged to an IBM compatible computer. We also achieved the enhancement of the system through the manipulation of the dilution rate and the use of thermo-lux fusion strains. Finally, this system is now being implemented to a drinking water reservoir and river for remote sensing as an early warning system.     

Dynamical modelling of an activated sludge system of a petrochemical plant operating at high temperatures.

The Mexican petrochemical industry, Morelos S.A. de C.V., is one of the biggest and more important petroleum industries in Mexico and Latin America. It has an activated sludge system to treat its wastewater flow, which is approximately 7,000 m3/d. The wastewater contains volatile organic carbon substances classified as toxics. The old surface aeration system was changed for fine bubble diffusers; however, one major drawback of the new aeration system is that the temperature in the bioreactor has increased due to the compression of the air, which at the compressor exit reaches 85 degrees C. This effect results in the temperature in the bioreactor attaining 32 degrees C during the fall, whereas in the spring and summer, the bioreactor temperature reaches higher values than 40 degrees C. The high temperatures reduce the microorganism activity and cause a higher volatilisation rate of volatile compounds, among other effects, which affect the performance of the biological treatment. This work was performed to obtain a better modelling of the wastewater treatment from the petrochemical industry. The model describes the effect of the temperature on the performance of the biological treatment. The model was obtained from tests that were carried out in laboratory reactors with 14 L capacity, which were operated at different temperatures (from 30 to 45 degrees C), with the same wastewater and conditions as the actual system.     

Overcompensation as a Partial Solution to Commitment and Renegotiation Problems: The Case of Ex Post Moral Hazard

In a Costly State Verification world, an agent who has private information regarding the state of the world must report what state occurred to a principal, who can verify the state at a cost. An agent then has what is called ex post moral hazard: he has an incentive to misreport the true state to extract rents from the principal. Assuming the principal cannot commit to an auditing strategy, the optimal contract is such that: (1) the agent's expected marginal utility when there is an accident (high‐ and low‐loss states) is equal to his marginal utility when there is no accident; (2) the lower loss is undercompensated, while the higher loss is overcompensated; and (3) the welfare of the agent is greater under commitment than under no‐commitment. Result 2 is contrary to the results obtained if the principal can commit to an auditing strategy (higher losses underpaid and lower losses overpaid). The reason is that by increasing the difference between the high and the low indemnity payments, the probability of fraud is reduced.     

An integrated approach for solving urban water and wastewater crises in the Arabian Gulf States.

Various environmental and economic aspects of urban water and wastewater crises in a number of the Arabian Gulf States are discussed. An integrated approach, which considers simultaneously the problems of urban waters (shortage of water supply and problems associated with urban drainage) and those in connection with wastewater (i.e. environmental impact) is proposed. The feasible link between the main factors affecting these problems and the anticipated results encourage the implementation of the proposed approach. The conclusions suggest immediate municipal legislation.     

Evaluating the application of a decision support system in identifying adequate wastewater treatment for small communities. A case study: the Fluvia River Basin.

The identification of adequate wastewater treatment for small communities is a complex problem since it demands a combination of data from different sources, such as aspects of the community and landscape, the receiving environment and the available wastewater treatment technologies. The Catalan Water Agency (Agència Catalana de l'Aigua) considered using an EDSS (Environmental Decision Support System) as a tool to help water managers select the most adequate treatment for the urban wastewater of nearly 3,500 small communities in Catalonia (Spain). From that moment, EDSS was applied to all the river basins in Catalonia. In this paper the authors present the results obtained for the 76 small communities located in one of these river basins: the Fluvia River Basin. The characteristics of the community used in the reasoning process of the EDSS, the list of selected wastewater treatment alternatives, the technical environmental justification for the selected treatments and the reasons for discarding, favouring or disadvantaging them are presented. Finally, some results for the Fluvia River Basin are compared with those obtained in other Catalan river basins with different characteristics in order to evaluate which are the significant features in identifying adequate wastewater treatments.