CHOICE OF FLEXIBLE FUNCTIONAL FORMS: REVIEW AND APPRAISAL

Choice between alternative flexible functional forms has received little explicit treatment in many empirical agricultural studies. Theoretical criteria and empirical techniques for choosing between flexible functional forms are reviewed. Theoretical topics include definitions of flexibility, mathematical expansions, separability, and regular regions. Empirical techniques examined are Monte Carlo analysis, parametric modeling, bayesian inference, and nonnested hypothesis testing. Comparison of the full range of theoretical and empirical aspects may provide more credible and reliable empirical estimates when consumer or producer duality assumptions are appropriate in agricultural applications.Research Methods/ Statistical Methods,

MARKET DEMANDS FOR BAGGED, REFRIGERATED SALADS

Sales of newly introduced bagged, refrigerated salads grew at over 50% annually, during 1994-95. Consumption of bagged salads displayed marked seasonality despite year-round availability and uniform quality at more stable prices than head lettuce. Using scanner data from 44 areas, a single-equation demand model incorporating the effects of weather on seasonal consumption is estimated. Statistical tests of aggregation indicate that weather-induced seasonality varies significantly across areas, as do own- and cross- price elasticities. Econometric results suggest more seasonality in eating by people living in more northern latitudes, a pattern also observed by psychiatrists studying eating disorders.Food Consumption/Nutrition/Food Safety,

DEMAND FOR ORGANIC AND CONVENTIONAL FROZEN VEGETABLES

In this paper, we examine retail sales of organic and conventional frozen vegetables (broccoli, green beans, green peas, and sweet corn) using supermarket scanner data. Descriptive analysis includes comparisons of sales volume, prices, and market shares. Price and expenditure elasticities are estimated using the almost ideal demands system (AIDS).organic foods, frozen vegetables, almost ideal demand system, Consumer/Household Economics, Demand and Price Analysis,

TIME INTEGRATION: AGRIBUSINESS STRUCTURE FOR COMPETITIVE ADVANTAGE

Agribusiness,

MODEL SELECTION WITH TEMPORAL AND SPATIAL AGGREGATION: ALTERNATIVE MARKETING MARGIN MODELS

Marketing,

Modeling Florida Fresh Tomato Supply Response: Composite Switching Regressions with Variable Weather-Determined Lags

A supply-response model for Florida fresh tomatoes is specified to analyze the impacts of the U.S. Department of Commerce's suspension agreement which governs imports of fresh tomatoes from Mexico. The particular focus is on the impact of the "reference" price which causes Mexican imports in a given week to cease if import prices in the prior week fall to the reference price. Using weekly weather data, a growing degree day (GDD) variable is constructed which predicts week of first harvest and duration of harvest. The GDD variable is used to construct the appropriate, variable lag length for weekly acres planted in four Florida production regions. A composite switching-regime model is estimated in which the regime prior to the suspension agreement occurs at a known time. The other two regimes occur when Nogales f.o.b. price are "near" or not near the reference price. Preliminary results suggest weekly Florida shipments of fresh tomatoes are more own-price elastic when Nogales f.o.b. prices near the reference price.International Relations/Trade,

THE ADOPTION AND DIFFUSION OF LEVEL FIELDS AND BASINS

Strategic investments in agriculture often are lumpy and irreversible, with significant impacts on operating and fixed costs. Leveling cotton fields to zero slope in central Arizona is a strategic decision made by relatively younger farmers who are farming fine-textured soils in irrigation districts with higher expected water costs. The diffusion of the technology across the region between 1968-89 appears to be both a function of institutional changes (e.g., the Groundwater Management Act of 1980, the Central Arizona Project) and the long-run expected price changes induced by these new policies.Crop Production/Industries,

Social Network Capital and Academic Careers

Social Network Capital and Academic Careers: The Case of a College of Agriculture ABSTRACT The relationship between economic performance and various forms of capital anchors a significant portion of mainstream economic theory and applied economics. Human, physical and financial capital represent important factors in the production of goods and services. The label “capital” implies characteristics such as investment, accumulation, maintenance, depreciation, and transfer. Recently, social capital or social network capital (SNC) has received increased scholarly attention in the literature of sociology, business, and economics. Limited analysis, however, has been directed at the role of SNC in the academy. We hypothesize that academic success at the professorial level is determined by the stock of human (HC) and SNC and the value flows emerging from these stocks. We view SNC as a complement to HC, increasing the productivity of HC while holding all other factors constant. An analysis of SNC’s importance to academic career success should interest the academy as well as other large organizations (i.e. research laboratories, government agencies) with similar structures and incentive systems.Social capital, academic networks, human capital, Institutional and Behavioral Economics, Labor and Human Capital, Teaching/Communication/Extension/Profession,

EMERGENCE OF U.S. ORGANIC AGRICULTURE: CAN WE COMPETE?

This compilation of papers for principal papers session PP-03 at the AAEA 1998 Annual Meeting assesses the current status of the organic agriculture industry in the United States. Paper topics address production, market and certification issues faced by the industry, research challenges and emerging conditions shaping domestic and international markets.production, marketing, industry structure, international trade, certification, organic agriculture, Industrial Organization, International Relations/Trade, Marketing, Production Economics,

Phase-resolved HST/STIS spectroscopy of the exposed white dwarf in the high-field polar AR UMa

Phase-resolved HST/STIS ultraviolet spectroscopy of the high-field polar AR UMa confirms that the WD photospheric Ly alpha Zeeman features are formed in a magnetic field of ~200 MG. In addition to the Ly alpha pi and sigma+ components, we detect the forbidden hydrogen 1s0->2s0 transition, which becomes ``enabled'' in the presence of both strong magnetic and electric fields. Our attempt in fitting the overall optical+UV low state spectrum with single temperature magnetic WD models remains rather unsatisfactory, indicating either a shortcoming in the present models or a new physical process acting in AR UMa. As a result, our estimate of the WD temperature remains somewhat uncertain, Twd=20000+-5000K. We detect a broad emission bump centered at ~1445A and present throughout the entire binary orbit, and a second bump near ~1650A, which appears only near the inferior conjunction of the secondary star. These are suggestive of low harmonic cyclotron emission produced by low-level (M-dot~1e-13 Msun/yr) accretion onto both magnetic poles. However, there is no evidence in the power spectrum of light variations for accretion in gas blobs. The observed Ly alpha emission line shows a strong phase dependence with maximum flux and redshift near orbital phase phi~0.3, strongly indicating an origin on the trailing hemisphere of the secondary star. An additional Ly alpha absorption feature with similar phasing as the Ly alpha emission, but a \~700km/s blueshift could tentatively be ascribed to absorption of WD emission in a moderately fast wind. We derive a column density of neutral hydrogen of NH=(1.1+-1.0)1e18 cm**-2, the lowest of any known polar.Comment: 26 pages, 10 figures, AAS TeX 5.0, accepted for publication in the Astrophysical Journa