David Zilberman

Adoption of Agricultural Innovations in Developing Countries: A Survey

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The agricultural innovation process: Research and technology adoption in a changing agricultural sector

The chapter reviews the generation and adoption of new technologies in the agricultural sector. The first section describes models of induced innovation and experimentation, considers the political economy of public investments in agricultural research, and addresses institutions and public policies for managing innovation activity. The second section reviews the economics of technology adoption in agriculture. Threshold models, diffusion models, and the influence of risk, uncertainty, and dynamic factors on adoption are considered. The section also describes the influence of institutions and government interventions on adoption. The third section outlines future research and policy challenges.

The Econometrics of Damage Control: Why Specification Matters

The contribution of damage control agents to production differs fundamentally from that of standard inputs (lands, labor, capital). This paper develops an econometric model based on the key characteristics of damage control agents and examines its properties. It demonstrates that standard production function specifications overestimate damage control agent productivity and have erroneous implications for the evolution of damage control agent productivity and use in response to changing environments (e.g., the spread of pest resistance). It also proposes several alternative specifications and discusses methods for estimating them.

The Choices of Irrigation Technologies in California

This paper introduces an econometric technique to analyze the factors affecting the land shares of alternative irrigation technologies in agriculture. It estimates the likelihood of use of drip, sprinkler, and surface irrigation by fruit growers in the Central Valley of California. Higher water costs, the use of groundwater, the production of nuts, and location are found to increase the likelihood of using drip and sprinkler irrigation. The results are used to demonstrate the effectiveness of water price increases in inducing water conservation.

The Effects of Well Depth and Land Quality on the Choice of Irrigation Technology

This paper introduces a framework to study the effects of farm characteristics (land quality and well depth) and irrigation technology characteristics (application effectiveness and pressurization requirement) on a farmers choice of irrigation system. Conditions indicating how the adoption of drip or sprinkler irrigation affects water and energy demands are presented as well as conditions under which these technologies are likely to be adopted. Two functional forms for the production function (quadratic and Cobb-Douglas) are presented with realistic values of key parameters. The empirical analysis demonstrates the importance of using forms which are consistent with the classical three stages of production.

Challenge of biofuel: filling the tank without emptying the stomach?

Biofuels have become a leading alternative to fossil fuel because they can be produced domestically by many countries, require only minimal changes to retail distribution and end-use technologies, are a partial response to global climate change, and because they have the potential to spur rural development. Production of biofuel has increased most rapidly for corn ethanol, in part because of government subsidies; yet, corn ethanol offers at most a modest contribution to society’s climate change goals and only a marginally positive net energy balance. Current biofuels pose long-run consequences for the provision of food and environmental amenities. In the short run, however, when gasoline supply and demand are inelastic, they serve as a buffer supply of energy, helping to reduce prices. Employing a conceptual model and with back-of-the-envelope estimates of wealth transfers resulting from biofuel production, we find that ethanol subsidies pay for themselves. Adoption of second-generation technologies may make biofuels more beneficial to society. The large-scale production of new types of crops dedicated to energy is likely to induce structural change in agriculture and change the sources, levels, and variability of farm incomes. The socio-economic impact of biofuel production will largely depend on how well the process of technology adoption by farmers and processors is understood and managed. The confluence of agricultural policy with environmental and energy policies is expected.

The Economics and management of water and drainage in agriculture

The irrigation history of the San Joaquin Valley (Valley) is composed of several phases starting with individuals digging ditches and continuing to the present State Water Plan. Various institutions have developed to assist in the expansion of irrigation. These include the water companies ofthe last century and the water districts created by the Act of 1887. Irrigation has produced an enormous rise in the number of farms, population, and harvested acreage in the Valley. Agriculture in the Valley has changed over time. Initially it was cattle ranching with the prime product being the hides. Around the middle of the last century wheat production began and by the 1870s, following the arrival of the railroad, the Valley was a vast wheat land. Drought and reduced yields resulting from continual cropping began to reduce wheat acreage by the 1890s. This was accelerated by the expansion of irrigation and the increase of intensive agriculture. The major agricultural activities which have developed in the present century are: (1) Dairying, (2) vegetables, (3) orchard crops, and (4) cotton. These four activities accounted for about 82 percent of harvested land in 1987. The great expansion of irrigation was associated with the large increase in ground-water pumpage and the development of the Central Valley Project pumping northern California water to the Valley. The State Water Project now provides additional northern California water to the Valley. The expansion of irrigation has been accompanied by the rise of severe drainage problems which pose a significant threat to the future ofthe Valley. Continued ground-water pumpage is seriously depleting the regions ground-water basin and has produced land subsidence. The Valleys agricultural future is at risk due to: (1) The demand for water for higher valued uses such as municipal and industrial supplies; (2) the environmental need for additional freshwater to maintain the Sacramento!San Joaquin River Delta and San Francisco Bay Estuary; and (3) the necessity to solve the drainage problem. 10 BACKGROUND AND SETIING

A Model of Investment under Uncertainty: Modern Irrigation Technology and Emerging Markets in Water

This article develops a stochastic dynamic model of irrigation technology adoption. It predicts that farms will not invest in modern technologies unless the expected present value of investment exceeds the cost by a potentially large hurdle rate. The article also demonstrates that, contrary to common belief, water markets can delay adoption. The introduction of a market should induce farms with abundant (scarce) water supplies to adopt earlier (later) than they would otherwise. This article was motivated by evidence that, contrary to NPV predictions, farms wait until random events such as drought drive returns significantly above costs before investing in modern irrigation technologies. Copyright 2002, Oxford University Press.

Payments for ecosystem services and poverty reduction: concepts, issues, and empirical perspectives

Paying for the provision of environmental services is a recent policy innovation attracting much attention in both developed and developing countries. This innovation, referred to as ‘payments for ecosystem services’ (when the emphasis is on enhancing ‘nature’ services) or ‘payments for environmental services’ (when amenities provided by the built environment are also included) is referred to here as PES. PES programs aim to harness market forces to obtain more efficient environmental outcomes. Since so many opportunities for PES programs could involve farmers in poor regions, international aid agencies and private donors, looking for a double dividend, increasingly consider using PES programs as a potential way of meeting both social and environmental objectives.

Explaining Irrigation Technology Choices: A Microparameter Approach

Water price reforms are increasingly being used to encourage improvements in irrigation efficiency through technology adoption. A microparameter approach based on field-level data is used to assess the effect of economic variables, environmental characteristics, and institutional variables on irrigation technology choices. The results show that water price is not the most important factor governing irrigation technology adoption; physical and agronomic characteristics appear to matter more. The results demonstrate the importance of using micro-level data to determine the effects of asset heterogeneity and crop type on technology adoption. Copyright 1996, Oxford University Press.