Measuring market power in the Greek food and beverages manufacturing industry

This paper measures the degree of market power of the Greek food and beverages manufacturing industry over the period 1983–2007 at the three-digit SIC level. The present study also estimates the “deadweight” loss and the reduction of consumers’ income due to the possible existence of market power in the Greek food and beverages manufacturing industry. Based on Bresnahan’s (1989) conjectural variation model, three different approaches are used to investigate competitive conditions of the Greek food and beverages manufacturing industry. The first approach assesses the extent of market power of the whole industry over the period 1983–2007; the second approach tests the degree of market power in each one of the nine sectors of the industry over the whole period, i.e. 1983–2007; and the third one estimates the extent of market power for the whole Greek food and beverages manufacturing industry for specific sub-periods of the period 1983–2007. The methodology of Dickson and Yu (1989) is adopted to measure the welfare losses. The empirical results indicate the presence of some degree of market power in the whole Greek food and beverages manufacturing industry as well as in each one sector of the industry during the period 1983– 2007 and, as a result, the existence of welfare losses. In addition, the empirical findings support the presence of some degree of market power for each sub-period of the period 1983– 2007 in the whole Greek food and beverages manufacturing industry and the existence of welfare losses.Conjectural variation, Greek food and beverages manufacturing industry, Market power, Welfare losses, Agribusiness, D43, D60, L66, Q10,

Organizational Innovation in Russian Agriculture: The Emergence of "New Agricultural Operators" and Its Consequences

After almost a decade of downsizing, Russian agriculture has been steadily growing since the end of 90's against the background of deep organizational changes and innovations. The traditional collective farming segment is the key target and subject of innovations. Outside investors and operators have acquired control over farm assets from the primary nominal owners and possessors. As a result, exceptionally large commercial farm operations - "agroholdings" - are being created. Both inside and outside innovators are introducing organizational changes such as vertical integration, custom and contract farming, land leasing, machinery sharing and others. The paper discusses size, scope and character of the ongoing innovations and their short and long-term consequences.agroholdings, contract and custom farming, new agricultural operators, integration, Industrial Organization,

Breakdown of adiabatic transfer of light in waveguides in the presence of absorption

In atomic physics, adiabatic evolution is often used to achieve a robust and efficient population transfer. Many adiabatic schemes have also been implemented in optical waveguide structures. Recently there has been increasing interests in the influence of decay and absorption, and their engineering applications. Here it is shown that even a small decay can significantly influence the dynamical behaviour of a system, above and beyond a mere change of the overall norm. In particular, a small decay can lead to a breakdown of adiabatic transfer schemes, even when both the spectrum and the eigenfunctions are only sightly modified. This is demonstrated for the generalization of a STIRAP scheme that has recently been implemented in optical waveguide structures. Here the question how an additional absorption in either the initial or the target waveguide influences the transfer property of the scheme is addressed. It is found that the scheme breaks down for small values of the absorption at a relatively sharp threshold, which can be estimated by simple analytical arguments.Comment: 8 pages, 7 figures, revised and extende

Optical properties of apple skin and flesh in the wavelength range from 350 to 2200 nm

Optical measurement of fruit quality is challenging due to the presence of a skin around the fruit flesh and the multiple scattering by the structured tissues. To gain insight in the light-tissue interaction, the optical properties of apple skin and flesh tissue are estimated in the 350-2200nm range for three cultivars. For this purpose, single integrating sphere measurements are combined with inverse adding- doubling. The observed absorption coefficient spectra are dominated by water in the near infrared and by pigments and chlorophyll in the visible region, whose concentrations are much higher in skin tissue. The scattering coefficient spectra show the monotonic decrease with increasing wavelength typical for biological tissues with skin tissue being approximately three times more scattering than flesh tissue. Comparison to the values from time-resolved spectroscopy reported in literature showed comparable profiles for the optical properties, but overestimation of the absorption coefficient values, due to light losses

A condensed matter realization of the axial magnetic effect

The axial magnetic effect, i.e., the generation of an energy current parallel to an axial magnetic field coupling with opposite signs to left- and right-handed fermions is a non-dissipative transport phenomenon intimately related to the gravitational contribution to the axial anomaly. An axial magnetic field emerges naturally in condensed matter in the so called Weyl semi-metals. We present a measurable implementation of the axial magnetic effect. We show that the edge states of a Weyl semimetal at finite temperature possess a temperature dependent angular momentum in the direction of the vector potential intrinsic to the system. Such a realization provides a plausible context for the experimental confirmation of the elusive gravitational anomaly.Comment: 5 pages, 3 figure

Two-Photon Polarization Interference for Pulsed SPDC in a PPKTP Waveguide

We study the spectral properties of Spontaneous Parametric Down Conversion in a periodically poled waveguided structure of KTP crystal pumped by ultra-short pulses. Our theoretical analysis reveals a strongly multimode and asymmetric structure of the two-photon spectral amplitude for type-II SPDC. Experimental evidence, based on Hong-Ou-Mandel polarization interference with narrowband filtering, confirms this result.Comment: Submitted for publicatio

Orange-Flesh Sweet Potato - Promising Partnerships for Assuring the Integration of Nutritional Concerns into Agricultural Research and Extension

Research Results from the Department of Policy Analysis MARD-Directorate of Economicsfood security, food policy, Mozambique, sweet potato, malnutrition, Crop Production/Industries, Food Security and Poverty, Q18,