Regional versus inter-regional efficiency in resource allocations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46106/1/168_2005_Article_BF01294884.pd

A benefit-cost model for the evaluation of on-site benefits of soil conservation projects in Mexico

Soil and water conservation measures can comprise a wide range of activities, both structural and non-structural. Their potential benefits range from protection and productivity increases of the directly affected lands to widely dispersed downstream benefits. While in most situations it is rather difficult to evaluate the latter, it can be shown that in many cases the direct upstream benefits are sufficiently large to justify soil and water conservation programs regardless of potential additional downstream benefits. A benefit-cost model was developed that compares program costs per unit of directly protected agricultural land with the net benefits resulting from two on-site consequences, land productivity enhancement from improved water conservation and elimination of productivity losses from gradual soil destruction. This model was applied to ongoing governmental programs in two Mexican states. The results show that benefits from the prevention of soil destruction are substantially larger than those from immediate productivity increases, although the latter were considered by Mexican authorities to represent the major program benefits.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46101/1/168_2005_Article_BF01284777.pd

Relative price changes and the benefits and costs of alternative power projects

What are the conclusions that we have to draw from the foregoing discussion? We must conclude that the prevailing practice of evaluating benefits and costs in terms of present costs and prices is not only likely to lead to an under-statement of actual costs, but also may lead to gross inefficiencies in project selection. This danger is particularly great in cases of hydro projects with long construction time horizons or long-term project sequences that depend for their feasibility on some common facility. While the need to estimate future price relationships may seem to introduce new uncertainties into project evaluations the use of prevailing prices is even less satisfactory. A somewhat inaccurate estimate of future changes, as long as it points in the right direction and as long as it is backed up by a sensitivity analysis that tests the effects of the assumptions on overall benefits and costs will provide a better and more realistic picture. Today this issue is of particular urgency since the traditional cost advantage of hydro over thermal alternatives is quickly disappearing. Given the very dramatic cost reductions expected from the introduction of second and third generation atomic power plants it becomes mandatory for any power system planner to take these expected changes explicitly into account.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46103/1/168_2005_Article_BF01324676.pd

Regional benefits in federal project evaluations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46108/1/168_2005_Article_BF01285516.pd

Input and output constraints affecting irrigation development

In many of the developing countries the expansion of irrigated agriculture is used as a major development tool for bringing about increases in agricultural output, rural economic growth and income distribution. Apart from constraints imposed by water availability, the major limitations considered to any acceleration of such programs are usually thought to be those of costs and financial resources. However, as is shown on the basis of empirical data drawn from Mexico, in reality the feasibility and effectiveness of such development programs is even more constrained by the lack of specialized physical and human factors on the input and market limitations on the output side. On the input side, the limited availability of complementary factors such as, for example, truly functioning credit systems for small-scale farmers or effective agricultural extension services impose long-term constraints on development. On the output side the limited availability, high risk, and relatively slow growth of markets for high-value crops sharply reduce the usually hoped-for and projected profitable crop mix that would warrant the frequently high costs of irrigation investments. Three conclusions are drawn: 1. (1) Factors in limited supply have to be shadow-priced to reflect their high opportunity costs in alternative uses.2. (2) Re-allocation of financial resources from immediate construction of projects to longer-term increase in the supply of scarce, highly-trained manpower resources are necessary in order to optimize development over time.3. (3) Inclusion of high-value, high-income producing crops in the benefit-cost analysis of new projects is inappropriate if these crops could potentially be grown in already existing projects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24377/1/0000646.pd

About the Influence of Line-shaped Inclusions on the Path of Fatigue Cracks

AbstractSecure findings on the propagation behavior of fatigue cracks are essential for the evaluation of the safety of components and structures. Therefore the growth of cracks in the vicinity of material boundaries, whereas also accidental inclusions represent such material boundaries, has to be considered, too. Depending on the way an initial crack enters the region of influence of such a material boundary, the crack may grow towards or away from the material boundary. In both cases a curved crack path results that cannot be explained with the global loading but obviously with different stiffness relations

Pricing irrigation water in Mexico: Efficiency, equity and revenue considerations

The withdrawal of water for irrigation in the dryer regions of Mexico already accounts for some 91% of potential availability. Further expansion of irrigated acreage, therefore, must rely more on increased water use efficiency rather than increased supply from engineering works. A prime instrument to bring about such an improvement could be an appropriate water pricing structure. The first three sections of the paper present the conceptual issues involved, as well as the empirical findings which show that irrigation farmers pay, on average, less than 10% of actual water costs. Water use efficiencies are shown to be less than 50% but are markedly higher in irrigation districts with volumetric compared to those with fixed water charges. The fourth section develops some representative pricing structures that are designed to account for both efficiency and income distributional goals, while the last one addresses some of the likely implementation problems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46100/1/168_2005_Article_BF01287246.pd