I examine the behavior of inventories and their role in the short-run dynamics of commodity production and price. Competitive producers of a storable commodity react to price changes by balancing costs of changing production with costs of changing inventory holdings. To determine these costs, I estimate a structural model of production, sales, and storage for copper, heating oil, and lumber. I ...

Marginally vitamin A-deficient 1-d-old chickens capable of remaining healthy for at least 6 weeks were produced using a two-generation model. In this model, hens fed on diets with a limited vitamin A content were used to obtain 1-d-old chickens which were marginally deficient in vitamin A. Only hens with a narrow range of plasma retinol values (0.60-0.85 mumol/l) were satisfactory for this purp...

According to “Hotelling rule” price of an “exhaustible resource” exceeds its marginal cost of production in perfect competition equilibrium by amount equal to the opportunity cost of depleting the resource now rather than next periods. This cost is called “scarcity rent”. Oil price exceeds its marginal extraction costs significantly. This can be attributed two different sources: effect of scarc...

The objectives of this research were to investigate influences of energy inputs and energy forms on output levels and evaluation of CO2 emissions for hazelnut production in Guilan province of Iran. Moreover, the sensitivity analysis was done by marginal physical productivity (MPP) method for energy inputs and energy using linear regression. Initial data were collected from 120 orchar...

The Production Possibility Set (PPS) is defined as the set of all inputs and outputs of a system in which inputs can produce outputs‎. ‎In Data Envelopment Analysis (DEA)‎, ‎it is highly important to identify the defining hyperplanes and especially the strong defining hyperplanes of the empirical PPS‎. ‎Although DEA models can determine the efficiency of a Decision Making Unit (DMU)‎, ‎but they...

the non-differentiability and implicit definition of boundary of production possibility set (pps) in data envelopment analysis (dea) are two important difficulties for obtaining directional characteristics, including different elasticity measures and marginal rates of substitution. also, imposing weight restrictions in dea models have some shortcomings and misunderstandings. in this paper we ut...

The lignocellulose in forage crops represents a second generation of biomass feedstock for conversion into energy-related end products. Some of the most extensively studied species for cellulosic feedstock production include forages such as switchgrass (Panicum virgatum L.), reed canarygrass (Phalaris arundinacea L.), and alfalfa (Medicago sativa L.). An advantage of using forages as bioenergy ...

To achieve food and energy security, sustainable bioenergy has become an important goal for many countries. The use of marginal lands to produce energy crops is one strategy for achieving this goal, but what is marginal land? Current definitions generally focus on a single criterion, primarily agroeconomic profitability. Herein, we present a framework that incorporates multiple criteria includi...