Economic analysis of different options in integrated pest and soil fertility management in maize systems of Western Kenya

The major biotic constraints to the production of maize, the major staple food in Western Kenya, are field pests such as Striga and stem borers, and low soil fertility. To counter these constraints, new cropping systems have been developed, including “push‐pull,” rotations with promiscuous soybean varieties and green manure crops, and imidazolinone resistant‐ (IR‐) maize. To analyze the technical and economic performance of these technologies, both with and without fertilizer, on‐farm researcher‐managed long‐term trials were implemented over six seasons in two sites each in Vihiga and Siaya districts of Western Kenya. The economic results, based on marginal analysis using a multioutput, multiperiod model, show that the new cropping systems with fodder intercropping (push‐pull) or soybean rotations were highly profitable. Push‐pull is more profitable but requires a relatively high initial investment cost. Green manure rotation, IR‐maize, and fertilizer all increased yields, but these investments were generally not justified by their increased revenue. We argue that research on rotation and cropping systems to tackle pest and soil fertility problems in Africa deserve more attention. This will require increased collaboration between agronomists and economists to set up long‐term experiments with new cropping systems to develop proper economic models.     

Does access to improved grain storage technology increase farmers' welfare? Experimental evidence from maize farming in Ethiopia

Seasonal price variability for cereals is two to three times higher in Africa than on the international reference market. Seasonality is even more pronounced when access to appropriate storage and opportunities for price arbitrage are limited. As smallholder farmers typically sell their production after harvest, when prices are low, this leads to lower incomes as well as higher food insecurity during the lean season, when prices are high. One solution to reduce seasonal stress is the use of improved storage technologies. Using data from a randomised controlled trial, in a major maize-growing region of Western Ethiopia, we study the impact of hermetic bags, a technology that protects stored grain against insect pests, so that the grain can be stored longer. Despite considerable price seasonality—maize prices in the lean season are 36% higher than after harvesting—we find no evidence that hermetic bags improve welfare, except that access to these bags allowed for a marginally longer storage period of maize intended for sale by 2 weeks. But this did not translate into measurable welfare gains as we found no changes in any of our welfare outcome indicators. This ‘near-null’ effect is due to the fact that maize storage losses in our study region are relatively lower than previous studies suggested—around 10% of the quantity stored—likely because of the widespread use of an alternative to protect maize during storage, for example a cheap but highly toxic fumigant. These findings are important for policies that seek to promote improved storage technologies in these settings.     

Simplified Risk Analysis in Agricultural Extension

Attention is given to the major methods of assessing risk in order to make choices. The literature frequently reports studies on mean-variance (E-V) analysis and stochastic dominance rules. Both of these methods are compared, in an agricultural application, with the approach outlined by Hanoch and Levy. The empirical results suggests that Hanoch and Levy's criterion appear to reduce the size of the risk-efficient set, and that the sets of recommendations from the methods under comparison were consistent. The two recommendations generated by Hanoch and Levy's rule were found to be reasonable for this particular decision process.     

CONCEPTUALIZATION OF ASSETS AND LIABILITIES

The conceptualization of assets and liabilities is fundamental to an understanding of financial accounting. It is often maintained that assets and liabilities represent economic resources and economic obligations, respectively, but that not all economic resources are assets and not all economic obligations are liabilities — a somewhat confusing state of affairs. This paper presents a schema for distinguishing assets from economic resources and liabilities from economic obligations based on the authoritative literature in the United States, Australia, Canada and Great Britain. The schema should be useful for clarifying certain financial accounting controversies concerning income taxes, leases, pension benefit payments and executory contracts.     

On the Contemporary Commodity Structure of World Trade Patterns: An Empirical Assessment

For about 150 years, international trade theory has mostly highlighted trade in consumption goods. Such a modeling approach was likely supported by the then prevailing commodity structure of world trade. This paper shows that – at least since 1970 – only about 20 per cent of commodity trade has taken place in consumables, the remainder being intermediates and capital goods. Theoretically, this evidence suggests a move in the modelling strategy for traded goods: from utility functions to production functions. Sanyal and Jones' "new trade theory" (1982) does precisely that. In addition, some crucial research challenges emerge. These relate to dynamic changes in some general characteristics of production technologies throughout the world.     

A meta-analysis of community-based studies on quality protein maize

Biofortification, or the improvement of nutritional quality in food crops, is a promising strategy to combat undernutrition, particularly among the rural poor in developing countries. However, traditional methods of impact assessment are inadequate for biofortified crops, as they do not consider their nutritional benefits. Evidence for the nutritional impact of maize varieties with improved protein quality, collectively known as quality protein maize (QPM), was evaluated using meta-analysis of randomized, controlled studies in target communities. A new and generalizable effect size was proposed to quantify the impact of QPM on a key outcome, child growth. The results indicated that consumption of QPM instead of conventional maize leads to a 12% (95% CI: 7–18%) increase in the rate of growth in weight and a 9% (95% CI: 6–15%) increase in the rate of growth in height in infants and young children with mild to moderate undernutrition from populations in which maize is the major staple food. The proposed effect size and use of bootstrapping to determine statistical significance addressed some methodological limitations in the existing studies.     

An alternative procedure for taking a random sample

Summary The procedure proposed consists in going through the population to be sampled item by item deciding each time with probability p whether the item at hand shall be incorporated in the sample. The "distances" between successive items in the sample will then form a random sample from a geometric distribution. A series of these random distances can easily be produced on a computer and can be conveniently used for taking the sample required. In some cases this method may have its advantages over the conventional use of a table of random numbers.