bluuebunny/crossref_metadata_2025 huggingface dataset:
Technical Change, Land Quality, and Income Distribution: A General Equilibrium Analysis
Authors: Coxhead Ian A. , Warr Peter G. , Crawford John
Published: July 2006

This paper investigates the distributional effects of technical progress in agriculture. A small computable general equilibrium model is developed in which agricultural production occurs in two environments with fixed land resources of different quality. The analytical structure permits not only the rate but also the factor biases of technical change to differ between environments. Distributional results are generated for several classes of households distinguished both by their ownership of factors and by their consumption patterns. The results demonstrate that technical change produces distributional outcomes which are highly sensitive to its factor biases and to prior differences in land quality.
Private Property Rights and Forest Preservation in Karnataka Western Ghats, India
Authors: Bhat M. G. , Huffaker R. G.
Published: July 2006

Areca nut orchard owners have been mulching their orchards with foliage from surrounding government‐owned deciduous forests at an average rate that may well deplete foliage within a decade, thereby endangering the long‐term viability of the region's most profitable agricultural enterprise. A bioeconomic model of areca nut production is formulated to determine the circumstances under which privatization of forest resources in the hands of orchard owners will stem this rapid depletion. An empirical application suggests that foliage is not currently sufficiently abundant to survive privatization; however, the prospects for preservation can be increased with the imposition of a preprivatization period of regulated use.
Incorporating Technological Change in Diffusion Models
Authors: Knudson Mary K.
Published: July 2006

The theoretical and empirical implications of a static and dynamic logistic diffusion model are compared. The dynamic model relaxes some assumptions of the static model by allowing for a flexible adoption ceiling, for changes in the technology, and for disadoption. Both models were used to estimate the diffusion of semi‐dwarf wheat varieties in the United States. The dynamic model provides a better fit to the data and provides additional insights into the economic determinants of adoption. In particular, the importance of technological change in other areas (here, in fertilizer) on the diffusion path of an innovation was shown.
Incorporating Stochastic Variables in Crop Response Models: Implications for Fertilization Decisions
Authors: Dai Qi , Fletcher Jerald J. , Lee John G.
Published: July 2006

Most crop‐decision models focus on output variation in response to nonstochastic inputs. Little attention has been given to the effects of stochastic factors on the input‐use decision. A crop‐decision model is developed to examine the impact of soil moisture on the nitrogen fertilization decision. The model is applied to 15 different soil and weather conditions for corn production in Indiana. Based on estimated response functions, the profit maximizing nitrogen application rate varies from 156 to 185 pounds of actual nitrogen (N) per acre. We evaluate the expected economic losses arising from applying to one set of conditions a rate deemed optimal for another.
An Animated Instructional Module for Teaching Production Economics With 3‐D Graphics
Authors: Debertin David L.
Published: July 2006

An animated instructional module is described for illustrating key production economics concepts. The module uses three‐dimensional production surfaces and two‐dimensional contour maps. Two graphics programs are used together to construct diagrams that neither program could produce alone. Module sequences are based on the “classical” two‐factor, one‐output model, using a production function consistent with textbook diagrams. Although primarily for upper‐division undergraduate or beginning graduate production economics courses, the instructional module provides a useful instructional supplement for advanced students. A free disk copy of the module for use on a personal computer is available from the author.
Procreation, Fishing, and Hunting: Renewable Resources and Dynamic Planar Systems
Authors: Nerlove Marc
Published: July 2006

Many problems in the economics of renewable resources can be put in the form of a dynamic planar system. This paper provides analytic and graphical methods for the study of the global dynamics, existence of stationary points, and local stability properties of such systems, and applies these methods to problems of (1) population and environmental quality; (2) exploitation of a stock of fish; and (3) the economics of the pleistocene extinctions and the origins of agriculture.
A Conjectural Variations Model of Reduced Japanese Milk Price Supports
Authors: Suzuki Nobuhiro , Lenz John E. , Forker Olan D.
Published: July 2006

Conjectural variations are estimated to determine the degree of imperfection in the Japanese milk market. Estimated conjectural variations indicate that the Japanese milk market is imperfectly competitive but is becoming more competitive. Our comparative static analysis indicates that when the milk support price is reduced, the fluid milk price will decline less under the current imperfectly competitive structure than it would under a competitive structure.
Productive and Predatory Public Policies: Research Expenditures and Producer Subsidies in Agriculture
Authors: de Gorter Harry , Nielson David J. , Rausser Gordon C.
Published: July 2006

Governments are postulated to maximize a political preference function in choosing two policy instruments: research expenditures (a productive policy) that improve social welfare and production subsidies (a predatory policy) that incur deadweight losses. Each policy affects the distribution of income between producers and consumers. Governments determine the optimal mix of policies, taking into account interaction effects between research and subsidy expenditures. In addition to providing an explanation for underinvestment in research, the paper determines conditions under which research and subsidy policies are complementary. Such conditions are shown to characterize U.S. agriculture. Underinvestment in research is therefore less severe than in some other countries.
Cholesterol Information and Shell Egg Consumption
Authors: Brown Deborah J. , Schrader Lee F.
Published: July 2006

U.S. per capita shell egg consumption has declined steadily since 1955 despite a falling real price. This paper investigates how information about cholesterol, as measured by a newly constructed index based on medical journal articles, has affected U.S. demand for shell eggs. The results of a fixed coefficient model indicate that information on the links between cholesterol and heart disease had decreased per capita shell egg consumption by 16% to 25% by the first quarter of 1987. A simple changing coefficient model indicates that cholesterol information has changed shell eggs' own price and income elasticities, so that the 1955–87 falling egg price and rising income increased egg consumption less than they otherwise would have.
Valuing Trade‐Offs between Net Returns and Stewardship Practices: The Case of Soil Conservation in Saskatchewan
Authors: Van Kooten G. C. , Weisensel Ward P. , Chinthammit Duangdao
Published: July 2006

In this paper, a trade‐off function between net returns and soil quality is developed for farmers in southwestern Saskatchewan using a Markov decision model. The results show that farmers who are concerned with soil levels or stewardship employ chem‐fallow more often at lower soil moisture levels and also tend to crop more intensively to conserve soil. The major conclusion is that concern for soil quality, as documented by some researchers, does have practical significance in changing agronomic practices; but, when soil is relatively deep, it takes a fairly substantial concern about soil quality before it is possible to distinguish clearly the agricultural practices of farmers who are truly concerned with stewardship from those who are not.
Risk Analysis of Tillage Alternatives with Government Programs
Authors: Williams Jeffery R. , Llewelyn Richard V. , Barnaby G. Art
Published: July 2006

Stochastic dominance analysis of two tillage systems, conventional tillage and no‐tillage, for five crop rotations, wheat‐fallow, grain sorghum‐fallow, continuous wheat, continuous grain sorghum, and wheat‐grain sorghum‐fallow, shows that risk‐averse managers prefer a conventional tillage wheat‐sorghum‐fallow system. Small changes in production costs or yields lead to indifference between this system and the no‐tillage wheat‐sorghum‐fallow and no‐till and conventional wheat‐fallow systems. Participation in the basic government commodity program generally increases average net returns and lowers variation of returns. Government commodity program payments calculated under a variety of scenarios do not generally encourage the use of no‐till practices for grain sorghum and wheat in the central Great Plains.
Economies Education in a Workshop Setting: Agricultural Business Plan Training in an Emerging Democracy and Market Economy
Authors: Miller Bill R. , Bahn H.M. , Drygas M. , Rust C.H.
Published: July 2006

Workshop education in business planning is one of the most important tools of transition from a centrally planned economy to a market economy. Business planning progressed from a “buzz word” among Polish Extension advisors in 1991 to more than 50,000 business plans completed by the end of 1994. An interactive workshop, transferrable to any transition economy, allowed participants to enter a workshop with data and prior experience in a command economy and emerge with a plan to implement in a market economy.
Supply and Demand Factors for Organic Produce
Authors: Park Timothy A. , Lohr Luanne
Published: July 2006

Although the organic produce industry is growing dramatically, little is known about market structure. We estimate a system of reduced‐form equations to evaluate supply and demand factors that influence equilibrium farm price and quantity in wholesale markets for organic broccoli, carrots, and lettuce. In the long run, demand factors dominate supply factors. Reduced wholesaling costs, increased margins by which organic wholesale price exceeds nonorganic price, and higher consumer income stimulate both farm price and output. Increasing the nonorganic farm price decreases equilibrium quantity of organics. Market expansion strategies should target consumers and wholesalers.
Measuring Effective Protection as a Superlative Index Number: An Application to European Agriculture
Authors: Bureau Jean‐Christophe , Kalaitzandonakes Nicholas G.
Published: July 2006

In this study duality and the theory of superlative index numbers are used to obtain a theoretically consistent Effective Protection Rate (EPR) index that imposes no a priori restrictions on input‐output substitution possibilities. Within this framework, EPRs are estimated for European agriculture over the period 1973 to 1989. The empirical results demonstrate that maintaining zero input/output substitutability—a restriction embedded in all common protection measures—can lead to false results about the level of protection both across countries and time.
Separability and the Shadow Value of Leisure Time
Authors: Larson Douglas M.
Published: July 2006

Recreation choices are often viewed as short‐run decisions conditioned on longer‐run labor supply. Using weak separability to reflect this relationship, the wage rate is the shadow value of time for individuals who get no utility from work, whether or not they are observed to be trading time for money in the short run. This result widens the circumstances under which the wage rate (not some fraction thereof) is the theoretically correct shadow value of time. Modifications to such a conclusion are developed for cases in which work is a source of utility and in which the first‐stage choice is not continuous.
Propensity to Consume Farm Family Disposable Income from Separate Sources
Authors: Carriker Gordon L. , Langemeier Michael R. , Schroeder Ted C. , Featherstone Allen M.
Published: July 2006

Farm family disposable income is generated from farm operations, off‐farm sources, and government payments. If these three income components are fungible (a dollar from one source is a perfect substitute for a dollar from another source), then the propensities to consume each should be the same. This study examines the farm family propensity to consume from separate income sources. Results indicate that the propensity to consume off‐farm income and government payments is higher than the propensity to consume farm income.
Cost Functions Under Production Uncertainty
Authors: Pope Rulon D. , Chavas Jean‐Paul
Published: July 2006

We characterize the cost functions which would be consistent with expected utility maximization when production is uncertain. It is not generally possible, assuming risk aversion, to use only expected output as the constraint in a cost minimization problem. In some leading cases, cost functions consistent with expected utility maximization are particularly useful because they are devoid of risk preferences.
The Lease‐Purchase Decision for Agricultural Assets
Authors: Ford Stephen A. , Musser Wesley N.
Published: July 2006

The decision to lease or purchase an asset is analyzed with methodology adapted from the corporate finance literature. The methodology allows determination of a break‐even lease payment using a minimum of information. Symmetry between the lessee and lessor is also examined. Effects of changes in the discount rate, marginal tax rate, capital rationing, and other parameters on break‐even lease payments are examined analytically and numerically. Analysis of differences in the parameters of the lessee and lessor identifies conditions under which markets for leasing arrangements will exist.
Imputing Input Characteristic Values from Optimal Commercial Breed or Variety Choice Decisions
Authors: Melton Bryan E. , Colette W. Arden , Willham Richard L.
Published: July 2006

Previous Input Characteristics Models (ICMs) are modified and extended to allow the economic values of individual genetic characteristics to be imputed, even when those characteristics are acquired in largely inseparable bundles such as in the animal breed or plant variety decision of commercial producers. Through analysis of the commercial breed selection decision for a representative beef producer, the extended ICM is shown to generally be more flexible, with less restrictive data requirements for estimation, than prior ICMs. Additional modifications of the extended ICM method of analysis are suggested to further enhance and broaden its applicability.
Model Choice in Consumer Analysis: Taiwan, 1970–89
Authors: Lee Jonq‐Ying , Brown Mark G. , Seale James L.
Published: July 2006

Expenditure data were used to study how income and prices influenced consumer demand in Taiwan during the last decade. Alternative differential demand models combining the features of the Rotterdam model and the Almost Ideal Demand System (AIDS) were tested. AIDS‐type demand responses describe Taiwanese consumer behavior better than do the other specifications.
Sampling and Aggregation Issues in Random Utility Model Estimation
Authors: Feather Peter M.
Published: July 2006

Measurement of nonmarket values often involves subjective judgments. Since these judgments may influence results, they should be carefully considered. I focus on an aspect of subjective choice relating to the estimation of random utility models. Such models require specification of each recreationalist's choice set. Whether an individual perceives his choice set as composed of all possible alternatives, a few popular alternatives, or collections of spatially aggregated alternatives is an important judgment affecting the conclusions.
Selling Import Quota Licenses: The U.S. Cheese Case
Authors: McCorriston Steve , Sheldon Ian M.
Published: July 2006

Recent discussions on U.S. trade policies suggest that import quotas should be auctioned to ensure the U.S. Treasury acquires the quota rent. However, studies estimating the potential benefits have ignored important details of import quota regimes and have assumed perfect competition and no exporter retaliation. We explore these three issues with an application to the U.S. cheese import quota regime. We show that when features of the U.S. dairy quota regime and structure of the cheese processing sector are accounted for, likely quota rents and potential welfare consequences of selling import licenses change significantly. While quota license sales may raise Treasury receipts, they may also cause a net welfare loss.
A Shadow‐Price Frontier Measurement of Profit Efficiency in Chinese Agriculture
Authors: Wang Jirong , Wailes Eric J. , Cramer Gail L.
Published: July 2006

A shadow‐price profit frontier model is developed to examine production efficiency of Chinese farm households. The model incorporates price distortions but retains the advantages of stochastic frontier properties. The shadow prices and shadow profit are derived through a behavioral profit function. Empirical results using household survey data show that the conventional assumption of profit maximization based on market prices is inappropriate. Farmers' resource endowment and education influence their allocative efficiency. Family size, per capita net income, and family members operating as village leaders are positively related to households' production efficiency. Reducing market distortions should increase farm households' production efficiency.
Safety‐First Criteria and Their Measures of Risk
Authors: Bigman David
Published: July 2006

A cardinal measure of risk which represents the safety‐first criteria is defined. The functional form of that measure is determined for a subgroup of risk‐averse agents that do not have money illusion. An empirical illustration of possible applications of that measure shows a method of identifying the subgroup of agents for which a given alternative dominates the others—in a group of risky alternatives when none of these alternatives dominates any of the others according to the first and the second criteria of stochastic dominance.
An Allais Measure of Production Sector Waste Due to Quotas
Authors: Fulginiti Lilyan E. , Perrin Richard K.
Published: July 2006

In this paper we adapt a partial equilibrium approach of Allais and Diewert to measure the efficiency loss in the producing sector due to quotas. The measure of waste is the additional profits available by reallocation subject to constraints that the welfare of persons and firms outside the sector is unaffected. It is relevant to a sector which faces fixed prices for some commodities, but endogenous prices for others. Tobacco quotas in the United States are estimated to have caused quota‐induced producer sector waste of approximately $@@‐@@95 million per year during 1950–82, or about 3% of the average value of the crop.
Estimating Dynamic Dual Models under Nonstatic Expectations
Authors: Luh Yir‐Hueih , Stefanou Spiro E.
Published: July 2006

In this paper we derive a system of equations depicting agents' dynamic decision rules under nonstatic price expectations. Based on the adjustment cost model of the firm, the integrability conditions which can serve to guide the specification of flexible functional forms are established. A two‐stage econometric model permitting empirical examination of both the expectations formation process and the dynamic structure of the industry is estimated using two different data series for U.S. production agriculture. The estimation results suggest evidence of the presence of nonstatic price expectations in dynamic dual models for U.S. production agriculture.
Household Demand in Rural China: A Two‐Stage LES‐AIDS Model
Authors: Fan Shenggen , Wailes Eric J. , Cramer Gail L.
Published: July 2006

A complete demand system of Chinese rural households is estimated using a two‐stage LES‐AIDS model and pooled provincial and time‐series data from 1982 to 1990. For commodity groups (food, clothing, fuel, housing, and other commodities), demand is price‐inelastic. Housing and other commodities are luxury goods, while clothing and food are necessities. Within the food group, price elasticities range from −0.005 to −0.63. Expenditure elasticities are lower for grains and higher for meat, tobacco, and alcohol. The results imply a gap between food demand and supply growth. Therefore, China will face pressure to import food.
Measuring Welfare Benefits from Improvements in Storage Technology with an Application to Tunisian Potatoes
Authors: Fuglie Keith O.
Published: July 2006

A multimarket model is used to explore equity and efficiency implications of improving crop storage technology. Two types of technical change are explored. Producers capture most of the benefits from new technology that reduces the cost of marketing inputs, whereas consumers gain more from technologies that reduce storage losses. In an application of the model to potatoes in Tunisia, improved pest control during storage is estimated to have significantly reduced seasonal variation in market prices and quantities during the 1980s. The rate of return to research on potato storage is estimated to lie between 44% and 74%.
A Positive Theory of Agricultural Protection
Authors: Swinnen Johan F. M.
Published: July 2006

The present paper analyses the political economy of agricultural protection in a general equilibrium framework. Rational politicians offer protectionist policies in return for political support from their constituency. Individuals in the economy have different factor endowments. Politicians exploit these differences in establishing redistributive policies when maximizing political support. Changes in economic variables—such as the urban‐rural income gap, capital intensity, the share of agriculture in total output and total employment, and the share of food in consumer expenditures—affect the political equilibrium policy. The analysis concludes that the observed correlation between economic development and agricultural protection is caused by a multiplicity of factors.
Production and Investment Decisions Under Sunk Cost and Temporal Uncertainty
Authors: Chavas Jean‐Paul
Published: July 2006

Building on Glenn Johnson's asset fixity theory, this article introduces sunk cost and temporal uncertainty in Jorgenson's neoclassical theory of investment. Under the assumption of risk neutrality, we show how sunk cost and temporal risk affect the implicit rental value of capital and investment and entry‐exit decisions. Results suggest there are important interactions between sunk cost and the effects of temporal uncertainty on production behavior.
Market Delineation and Demand Structure
Authors: Asche Frank , Steen Frode , Salvanes Kjell G.
Published: July 2006

This paper addresses the relationship between the cointegration approach to market delineation and the more traditional approach of analyzing the demand structure among different products in terms of degree of substitutability. Cointegration tests for market delineation and estimation of a dynamic system of demand equations are undertaken utilizing the same data set. The data set consists of three high‐quality seafood products in the European Union. The results are encouraging as the results from the two approaches are not only compatible, but are also complementary in the sense that they provide more information together than they do separately.
Optioning Agricultural Water Rights for Urban Water Supplies During Drought
Authors: Michelsen Ari M. , Young Robert A.
Published: July 2006

Option contracts for temporary use of irrigation water rights are evaluated as a less‐expensive institutional arrangement for providing drought insurance for urban water agencies. Desirable option contract provisions are suggested and a framework for evaluating the economic benefits of water supply options is proposed. An integrated analytical system simulating the hydrologic, institutional, and economic relationships for a case study area in northeast Colorado is developed to evaluate the economic feasibility of water supply option contracts. Estimated present value benefits and sensitivity analyses indicate that dry year water options are economically viable over a considerable range of conditions.
Credit Constraints, Farm Characteristics, and the Farm Economy: Differential Impacts on Feeder Cattle and Beef Cow Inventories
Authors: Bierlen Ralph , Dixon Bruce L. , Ahrendsen Bruce L. , Barry Peter J.
Published: July 2006

A recurrent topic in the macroeconomic literature is the financial accelerator—the notion that informational asymmetries introduce inefficiencies to financial markets which amplify and propagate the effects of real or monetary shocks. With the purpose of finding empirical evidence that is consistent with a financial accelerator operating in the cattle sector, inventory investment models are estimated with an appended cash flow variable. The inclusion of cash flow is motivated by the notion that investment by credit‐constrained farms should be sensitive to movements in internal funds. Results are consistent with the financial accelerator operating in the feeder cattle but not in the cow‐calf sector.
Quantifying the Effects of Sow‐Herd Management Information Systems on Farmers' Decision Making Using Experimental Economics
Authors: Verstegen Jos A.A.M. , Huirne Ruud B.M. , Dijkhuizen Aalt A. , Sonnemans Joep , Cox James C.
Published: July 2006

A pilot experiment was conducted to yield insight into whether laboratory experiments can be used as an alternative to surveys for determining the profitability of management information systems (MIS) in sow farming. In total, eighty‐six sow farmers, including fifty‐one farmers from an earlier survey study, participated in an individual decision‐making experiment, which was executed in a quasi‐experimental, nonequivalent control, pretest/posttest design. In an MIS group, MIS estimates were derived by within‐subjects comparisons of decision quality with and without MIS features. A baseline group was included to control for leaning or exhaustion effects during an experimental session. Subjects receiving MIS features significantly improved their decision making whereas subjects without MIS features did not. Correlation between MIS estimates of the survey study and MIS estimates of the experiment was not significant.
Spatial and Temporal Specialization in Forest Ecosystem Management Under Sole Ownership
Authors: Swallow Stephen K. , Talukdar Piyali , Wear David N.
Published: July 2006

“Ecosystem management” complicates forest management considerably. In this paper we extend the economic analysis of forestry to capture both the temporal and the spatial dimensions, allowing optimization of timber harvest decisions throughout an ecosystem. Dynamic programming simulations illustrate the implications for the simplest ecosystem, consisting of two forest management units. Results indicate that explicit recognition of ecological interactions, even between identical forest stands, may prescribe specialization through time and across space. Such spatial and temporal specialization leverages opportunities to provide ecosystem goods that may be foregone through reliance on “rules of thumb” derived from models that focus on the single stand.
Dynamic Optimal Management of Wind‐Erosive Rangelands
Authors: Hu Dayuan , Ready Richard , Pagoulatos Angelos
Published: July 2006

A bioeconomic model of livestock production from wind‐erosive rangelands is developed and optimized. Equations of motion capture the impact of topsoil stock on forage productivity and the protective effect of forage stock on soil loss from wind erosion. For overgrazed wind‐erosive rangelands, a lower discount rate provides incentives for lighter grazing, as does consideration of effect of stocking rates on animal performance. In the case where off‐site damages are large, internalizing off‐site effects would also encourage lighter grazing and hence promote sustainable production. An illustrative application of the model is also included.
Functional Forms, Exogenous Shifts, and Economic Surplus Changes
Authors: Zhao Xueyan , Mullen John D. , Griffith Gary R.
Published: July 2006

Conditions for exact welfare measures in equilibrium displacement modeling are examined. These relate to the functional form of supply and demand, the nature of the exogenous shift, and the definition of percentage changes. Approximation errors when these conditions are not met in empirical applications are investigated and analytical expressions for the errors derived. Significant errors are possible when a proportional shift is assumed. The assumptions underlying Alston and Wohlgenant's empirical findings are identified. The restriction that supply must be elastic is shown to be unnecessary.
Third‐Country Effects and Second‐Best Grain Trade Policies: Export Subsidies and Bilateral Liberalization
Authors: Alston Julian M. , Carter Colin A. , Sumner Daniel A. , Gray Richard
Published: July 2006

An incumbent export subsidy will affect the size and distribution of gains from bilateral trade liberalization but, in theory, may still permit increased trade volume and mutual benefits from freer trade. These points are illustrated using the case of Canada‐U.S. durum wheat trade, which grew rapidly following the 1989 Canadian‐U.S. Free Trade Agreement (CUSTA). An empirical analysis suggests that, given its Export Enhancement Program (EEP), the United States lost from freer trade in durum. Conversely, freer trade in durum means greater gains to the United States from eliminating EEP.
Environmental Externalities and the Optimal Level of Market Power
Authors: Gopinath Munisamy , Wu JunJie
Published: July 2006

This article derives the condition under which agricultural chemical producers' desire to under‐produce, associated with market power, exactly offsets the tendency to overproduce, due to their failure to consider externality costs of agricultural chemicals. This condition is satisfied when the price markup in the chemical industries equals the marginal environmental damages caused by chemicals. Our estimates of price markup for nitrogen, phosphate, and pesticides industries indicate that the welfare loss caused by market power is exactly offset by environmental benefits if the marginal pollution costs are, respectively, eight, nine, and twenty‐two cents for each dollar's worth of these chemicals.
The Effect of Income and Food Programs on Dietary Quality: A Seemingly Unrelated Regression Analysis with Error Components
Authors: Wilde Parke E. , McNamara Paul E. , Ranney Christine K.
Published: July 2006

This article employs new Food Guide Pyramid servings data to measure how food intake is affected by income and two food programs. The analysis uses a maximum likelihood estimator that combines the seemingly unrelated regression and one‐way error component models, to account for two types of intrahousehold correlations. Participation in the Food Stamp Program is associated with higher intake of meats, added sugars, and total fats. Participation in the Special Supplemental Nutrition Program for Women, Infants, and Children is associated with lower intake of added sugars.
Comparative Advantage and Government Budget Effects: An Application to the Grain Trade of the Former USSR
Authors: Liefert William M.
Published: July 2006

A model is developed for analyzing the relationship between trade according to comparative advantage, price policy, and government budget effects. The model is used to examine a debate in the USSR in its last years concerning the economic rationale of grain imports, one concern being government budgetary consequences. It appears that changing the mix of goods produced and traded such that grain imports would fall, which many Soviet economists advocated, would have unintentionally decreased state revenue. This is mainly because empirical evidence indicates that the former USSR had a comparative disadvantage in the production of grain.
Limiting Environmental Program Contradictions: A Demand Systems Application to Fishery Management
Authors: Ward Frank A. , Cole Richard A. , Deitner Robert A. , Green‐Hammond Catherine A.
Published: July 2006

Economically efficient natural resource policy requires the comprehensive management of environmental improvements over a system of sites. Use of multisite demand and benefit models can reduce the number and cost of environmental program contradictions. In this paper we present a multisite demand model that incorporates several quality dimensions for a system of New Mexico fishing sites. Use of the model permits managers to improve total welfare at lower cost by simultaneously distributing opportunity across all elements in resource users' choice sets. Model results show that errors that result from independently adding values of interdependent program elements approach 50%.
Nonparametric Tests of Profit Maximization in Oligopoly with Application to the Beef Packing Industry
Authors: Driscoll Paul J. , Kambhampaty S. Murthy , Purcell Wayne D.
Published: July 2006

In this paper, we develop new, nonparametric methods of testing for static profit maximization given noncompetitive behavior. Repeated application of the test yields “maximum likelihood” estimates of the degree of noncompetitive behavior. Using plant‐level data, these newly developed nonparametric methods are employed to test the hypothesis that beef packers are profit maximizers and to measure the extent to which packers influence prices in fed‐cattle markets.
Environmental Quality Preference and Benefit Estimation in Multinomial Probit Models: A Simulation Approach
Authors: Chen Heng Z. , Cosslett Stephen R.
Published: July 2006

Simulated maximum likelihood is used to estimate a random parameter multinomial probit model of destination choice for recreational fishing trips, formulated to accommodate varying tastes and varying perceptions of environmental quality across individuals. The restricted likelihood ratio test strongly rejects the independent probit model, which is similar to the independent logit model in both the parameter and benefit estimates. Furthermore, both the Krinsky‐Robb and bootstrapping procedures suggest that the benefit (standard deviation) of an environmental policy is found to be markedly lower (higher) when heterogeneous preferences are taken into account.
Flow‐of‐Funds Social Accounts for the Farm Sector
Authors: Penson John B. , Lins David A. , Irwin George D.
Published: July 2006

Flow‐of‐funds accounts and component sources‐and‐uses‐of‐funds statements relate changes in balance sheet accounts to income statements, describing movement from one balance sheet to the next. While the Federal Reserve System compiles a farm business sector sources‐and‐uses‐of‐funds statement consistent with and part of the national flow‐of‐funds accounts, the statement is not definitionally and conceptually consistent with published farm income and balance sheet accounts. An alternative farm sector sources‐and‐uses‐of‐funds statement is proposed that contains these features, and its potential applications and extensions are delineated.
Diabetic Foot Infections and Amputations Are All Too Common—Here’s What Could Move the Needle
Authors: Ruder Kate
Published: March 2024

This Medical News article discusses how multidisciplinary care teams, new drugs and devices, and practical solutions to socioeconomic factors could reduce diabetic foot infections and amputations.
Is Preoperative Optimization Right for Every Hernia Patient?
Authors: Bidwell Serena S. , Fry Brian T. , Telem Dana A.
Published: March 2024

This Viewpoint discusses developing a more nuanced preoperative optimization strategy for hernia repair that considers patient and disease factors to determine the right operation for the right patient at the right time.
Ion Mobility Spectrometry in Forensic Science
Authors: Joshi Monica
Published: March 2024

Ion mobility spectrometry
(
IMS
) is a valuable screening technique for hazardous chemicals in the field. It is prolifically used by law enforcement agencies, emergency response personnel, security agencies, and the military to detect explosives, illicit drugs, toxic industrial chemicals, and chemical warfare agents. IMS has been greatly successful, thanks to its portability, ruggedness, ability to operate at ambient pressures, low power requirements, simplicity, fast analysis times, and excellent sensitivity to target substances. This article outlines the current status of IMS and explores exciting innovations that could bring mobility principles to the laboratory, potentially improving the efficiency and accuracy of chemical analyses. The growth of
gas chromatography‐ion mobility spectrometry
(
GC–IMS
) and
ion mobility‐mass spectrometry
(
IM–MS
) could be an avenue for exploration in forensic science analysis. Both techniques improve upon IMS by addressing its weaknesses of poor resolution and susceptibility to mixtures. These are the primary obstacles to the laboratory use of IMS. As IMS continues to serve as a trace chemical monitor in the field, these developments in the coupling of IMS principles with other analytical techniques are giving mobility spectrometry a new purpose in the laboratory.
Rahnella
Authors: Brady Carrie L. , Denman Sandra
Published: March 2024

Rah'nel.la. L. fem. dim. n. suff.
‐ella
, diminutive ending; N.L. fem. dim. n.
Rahnella
, named after Otto Rahn, the German‐American microbiologist who proposed the name
Enterobacteriaceae
in 1937.

Pseudomonadota / Gammaproteobacteria / Enterobacteriales / Enterobacteriaceae / Rahnella

Rahnella
species are ubiquitous in the environment, regularly isolated from water, soil, and woody tree hosts as well as occasionally from human clinical samples. Cells are Gram stain negative, facultatively anaerobic, and motile rods. Species are psychrotolerant, able to grow at 4°C, and favor growth temperatures of 25–30°C. Carbon sources such as
d
‐maltose,
N
‐acetyl‐
d
‐glucosamine, α‐
d
‐glucose, and
d
‐mannose are readily assimilated. Species form a monophyletic clade when phylogenetic analysis is based on multilocus sequence analysis (MLSA) or whole‐genome sequences. The major fatty acids are C
16:0
and C
17:0
cyclo; the percentage of C
18:1
ω7
c
, summed feature 2 (iso‐C
16:1
and/or C
14:0
3‐OH), and summed feature 3 (C
16:1
ω7
c
and/or iso‐C
15:0
2‐OH) is variable, with some species exhibiting these fatty acids in larger amounts.

DNA G + C content (mol%)
: 51.3–53.7 (genome analysis).

Type species
:
Rahnella aquatilis
Izard et al. 1979, VL7.
Agathobaculum
Authors: Jeong Haeyoung , Chang Dong‐Ho , Kim Byoung‐Chan
Published: March 2024

A.ga.tho.ba'cu.lum. Gr. masc. adj.
agathos,
good; L. neut. n.
baculum
, small rod; N.L. neut. n.
Agathobaculum,
small rod beneficial bacterium.

Firmicutes / Clostridia / Eubacteriales / Oscillospiraceae / Agathobaculum

Agathobaculum
is a genus in the phylum
Firmicutes
, family
Oscillospiraceae
, order
Eubacteriales
, class
Clostridia
. Major fermentation end products are butyrate or acetate. Cells are obligately anaerobic, Gram‐stain‐positive, short, plump rods with widths and lengths ranging from 0.6 to 1.1 μm and 0.9 to 2.3 μm, respectively. No spores observed. Motile or nonmotile. Oxidase‐ and catalase‐negative. Cells occur singly, in pairs or chains. The major cellular fatty acids are C
16:0
, C
19
cyc 9, 10/:1, and C
14:0
from cells cultivated on DSM 104 agar plates for 2 days at 37°C. Cell wall contains meso‐diaminopimelic acid. DNA G + C content is 54.1–54.2 mol% (based on genome sequence). The genus currently comprises four species:
Agathobaculum butyriciproducens, Agathobaculum desmolans, Agathobaculum faecihominis,
and
Agathobaculum ammoniilyticum
. Optimal growth occurs at neutral pH and 37°C. Colonies of
Agathobaculum
are typically circular in form, convex in elevation, and white to yellowish in color. Based on results from the API 20A diagnostic kit, these bacteria use a diverse range of carbon sources including
d
‐glucose and
d
‐xylose but not
d
‐raffinose or
d
‐sorbitol. Members of the genus are found in human and animal feces. The type species is
Agathobaculum butyriciproducens
.

DNA G + C content (mol%)
: 54.1–54.2 (based on genome sequence).

Type species
:
Agathobaculum butyriciproducens
Ahn et al. 2016
VP
.
Node‐Reinforced Design and Selective Remanufacturing of Auxetic Lattice Structures
Authors: Zhang Meng , Xu Jiawen , Li Dongya , Liu Yu
Published: March 2024

Auxetic structures have many potential applications due to their counterintuitive deformation behavior and desirable mechanical properties. However, auxetic structures have some drawbacks, such as bending or rotational deformation of ligaments, leading to relatively low energy absorption (EA) performance and stability. In this article, designing nodal reinforcement of the sinusoidal lattice is proposed, and silicone rubber is selectively 3D‐printed inside the structure. As a result, under quasi‐static loading, the nodes of the structure improve the EA performance by 214%; compared to resin reinforcement, silicone‐rubber gradient reinforcement not only continues to provide load‐bearing capacity to the structure but also improves EA by a significant 112%. The assignment of silicone‐rubber nodes is found to effectively prevent the lateral slip of the structure after ligament rupture, resulting in a more stable and controllable deformation of the sinusoidally auxetic structure. Under low‐velocity dynamic loading, silicone rubber's designed nodes improve the structure's deformation stability more significantly and enhance the EA performance, which increases with the strain rate. The design and fabrication techniques have the potential for the integrated fabrication of multi‐material lightweight structures with complex shapes, superior mechanical properties, and multifunctional attributes.
High Ionic Conductive, Mechanical Robust Sulfide Solid Electrolyte Films and Interface Design for All‐Solid‐State Lithium Metal Batteries
Authors: Li Dabing , Liu Hong , Wang Chao , Yan Chong , Zhang Qiang , Nan Ce‐Wen , Fan Li‐Zhen
Published: March 2024

All‐solid‐state lithium batteries (ASSLBs) are considered a promising technology for next‐generation energy storage systems due to their inherent safety. However, the conventional laboratory‐scale ASSLBs reported to date are based on pellet‐type structures with thick solid electrolyte layers, leading to challenges related to low energy densities and poor electrochemical performance. In this study, porous adhesive poly(ethylene vinyl acetate) (PEVA) scaffolds and polytetrafluoroethylene (PTFE) binders are utilized to interweave sulfide solid electrolytes into freestanding films with an ultra‐low thickness of 40 µm, high ionic conductivity of 1.1 mS cm−1, and a high tensile strength of 74 MPa. To mitigate the reduction reaction between the PTFE binder and the lithium metal anode, a Li3N‐rich solid electrolyte interphase (SEI) in situ on lithium metal is formed, and the assembled symmetric cell shows excellent cycling stability within 800 h at the current density of 0.2 mA cm−2 and room temperature. Additionally, the ASSLBs using oxidatively stable Li2ZrCl5F in the composite cathode and the prepared solid electrolyte film demonstrate exceptional cycling performance and fast‐charging capability, with a high cell‐level energy density of 354.4 Wh kg−1. The ASSLBs prepared by coupling E‐LPSCl film and stable interface design exhibit excellent electrochemical performance and a high cell‐level energy density.
Biomimetic Eu@HOF Photoactivated Sponge as Ultrasensitive Auditory and Olfactory Sensor for Infrasound Wave Monitoring and Bimodal Information Integration
Authors: Zhu Kai , Yan Bing
Published: March 2024

The combination of multisensory stimuli in the somatosensory system enables humans to understand object comprehensive characteristics and make precise judgments. However, the development of auditory–olfactory bimodal flexible biomimetic sensors (FBSs) to mimic the function of biological perception of external stimuli still presents complex challenges. Herein, an auditory–olfactory bimodal FBS (1 and 2) is fabricated based on hydrogen‐bonded organic framework (Eu@HOF‐BPTC) integrated with melamine sponge. During the auditory sensing process, 1 can monitor sound with a maximum response frequency of 400 Hz. The auditory FBS performs ultrahigh sensitivity (41335.995 cps Pa−1 cm−2), ultrahigh precision (relative standard deviation < 0.20%), ultrafast response time (20 ms), ultralow detection limit (1.1039 Hz and 0.1083 dB), and great recyclability (148 cycles), which can also real‐time monitor infrasound waves within 4–20 Hz. Based on artificial intelligence, 2 as an olfactory FBS demonstrates excellent sensitivity with a ppm‐level response limit and desirable selectivity toward four odor molecules and realizes wearable on‐site detection. The FBS also completes auditory and olfactory signals integration and interoperability by means of human–machine interaction. The bimodal auditory–olfactory FBS is highly promising for implementing bimodal interaction, simulating complex biological neural system, and promoting environmental monitoring, disaster warning and health care.
Development of 3D Printed Biodegradable, Entirely X‐ray Visible Stents for Rabbit Carotid Artery Implantation
Authors: Shen Yihong , Tang Chaojie , Sun Binbin , Wu Yufan , Yu Xiao , Cui Jie , Zhang Mianmian , EL‐Newehy Mohamed , EL‐Hamshary Hany , Barlis Peter , Wang Wu , Mo Xiumei
Published: March 2024

Biodegradable stents are considered a promising strategy for the endovascular treatment of cerebrovascular diseases. The visualization of biodegradable stents is of significance during the implantation and long‐term follow‐up. Endowing biodegradable stents with X‐ray radiopacity can overcome the weakness of intrinsic radioparency of polymers. Hence, this work focuses on the development of an entirely X‐ray visible biodegradable stent (PCL‐KIO3) composed of polycaprolactone (PCL) and potassium iodate via physical blending and 3D printing. The in vitro results show that the introduction of potassium iodate makes the 3D‐printed PCL stents visualizable under X‐ray. So far, there is inadequate study about polymeric stent visualization in vivo. Therefore, PCL‐KIO3 stents are implanted into the rabbit carotid artery to evaluate the biosafety and visibility performance. During stent deployment, the visualization of the PCL‐KIO3 stent effectively helps to understand the position and dilation status of stents. At 6‐month follow‐up, the PCL‐KIO3 stent could still be observed under X‐ray and maintains excellent vessel patency. To sum up, this study demonstrates that PCL‐KIO3 stent may provide a robust strategy for biodegradable stent visualization.
Ingestible Artificial Urinary Biomarker Probes for Urine Test of Gastrointestinal Cancer
Authors: Xu Cheng , Xu Mengke , Hu Yuxuan , Liu Jing , Cheng Penghui , Zeng Ziling , Pu Kanyi
Published: March 2024

Although colorectal cancer diagnosed at an early stage shows high curability, methods simultaneously possessing point‐of‐care testing ability and high sensitivity are limited. Here, an orally deliverable biomarker‐activatable probe (termed as HATS) for early detection of orthotopic tumors via remote urinalysis is presented. To enable its oral delivery to the colon, HATS is designed to have remarkable resistance to acidity and digestive enzymes in the stomach and small intestine and negligible intestinal absorption. Upon reaction with a cancer biomarker in the colon segment, HATS releases a small fragment of tetrazine that can transverse the intestinal barrier, enter blood circulation, and ultimately undergo renal clearance to urine. Subsequently, the urinary tetrazine fragment is detected by bioorthogonal reaction with trans‐cyclooctene‐caged resorufin (TCO‐Reso) to afford a rapid and specific fluorescence enhancement of TCO‐Reso. Such signal readout is correlated with the urinary tetrazine concentration and thus measures the level of cancer biomarkers in the colon. HATS‐based optical urinalysis detects orthotopic colon tumors two weeks earlier than clinical serological tests and can be developed to a point‐of‐care paper test. Thereby, HATS‐based urinalysis provides a non‐invasive and sensitive approach to cancer screening at low‐resource settings.