firm size and its impact on the firm performance examined in all of economics historical periods from different point of view. meanwhile, productivity is one the most important performance index for each firm, therefore so many studies tries to survey firm size impact on it. in iran also, economics literature replete with productivity studies but the impact of size on it rarely seen between the...

this article examines the basic assumption of rational expectations hypothesis on iran's economy from 1966 to 2003. this assumption suggests the neutrality or ineffectiveness of money policy on the development of real variables of production and employment. the results from estimation of production equation do not support the significant influence of unanticipated component of money growth...

Context. Among optical stellar interferometers, the CHARA Array located at Mt Wilson in California offers the potential of very long baselines (up to 330 m) and the prospect of coupling multiple beam combiners. This paper presents the principle and the measured performance of VEGA, Visible spEctroGraph and polArimeter installed in September 2007 at the coherent focus of the array. Aims. With 0....

JEL classification: C65, D63, D71, D81 Mathematics Subject Classification (2000): 91B16

We find and study a five-parameter family of four-dimensional partial differential systems in two variables from the viewpoints of its symmetry and holomorphy properties. 1. Main results In this paper, we present a 5-parameter family of four-dimensional partial differential systems in two variables explicitly given by (cf. [3, 18]) dq1 = ∂H1 ∂p1 dt+ ∂H2 ∂p1 ds, dp1 = − ∂H1 ∂q1 dt− ∂H2 ∂q1 ds, d...

JEL classification: Q1 Q2 Q5 Most ecosystem services (ES) are neither priced nor marketed. Resource managers may fail to take into account degradation of unpriced services in their resource management decisions. Being able to estimate values for ES is fundamental to designing policies to induce resource users to provide (or improve) ES at levels that are acceptable to society. Conducting ecosys...

Producers are subject to similar production risks, and so their outputs are likely positively correlated. This is believed to be among the main impediments to the creation of viable production risk insurance markets, is a major motive for such stabilization schemes as the holding of buffer stocks, and is a prominent motive for private storage activities. Taking a state contingent perspective, t...

This paper compares the stability of the US Dual Banking system’s two bank groups, national and state banks, in light of the current financial crisis. The goal of the paper is to answer three distinct questions: first, is there a difference in the (balance sheet-) fragility between the two groups and, second, to what extent has the balance sheet fragility of both groups changed after the beginn...