Cooperative Data Exchange with Weighted Cost based on d-Basis Construction

We consider the cooperative data exchange problem, in which nodes are fully connected with each other. Each node initially only has a subset of the K packets making up a file and wants to recover the whole file. Node i can make a broadcast transmission, which incurs cost w_i and is received by all other nodes. The goal is to minimize the total cost of transmissions that all nodes have to send, which is also called weighted cost. Following the same idea of our previous work which provided a method based on d-Basis construction to solve cooperative data exchange problem without weighted cost, we present a modified method to solve cooperative data exchange problem with weighted cost. We present a polynomial-time deterministic algorithm to compute the minimum weighted cost and determine the rate vector and the packets that should be used to generate each transmission. By leveraging the connection to Maximum Distance Separable codes, the coefficients of linear combinations of the optimal coding scheme can be efficiently generated. Our algorithm has significantly lower complexity than the state of the art. In particular, we prove that the minimum weighted cost function is a convex function of the total number of transmissions for integer rate cases

Cooperative Data Exchange based on MDS Codes

The cooperative data exchange problem is studied for the fully connected network. In this problem, each node initially only possesses a subset of the $K$ packets making up the file. Nodes make broadcast transmissions that are received by all other nodes. The goal is for each node to recover the full file. In this paper, we present a polynomial-time deterministic algorithm to compute the optimal (i.e., minimal) number of required broadcast transmissions and to determine the precise transmissions to be made by the nodes. A particular feature of our approach is that {\it each} of the $K-d$ transmissions is a linear combination of {\it exactly} $d+1$ packets, and we show how to optimally choose the value of $d.$ We also show how the coefficients of these linear combinations can be chosen by leveraging a connection to Maximum Distance Separable (MDS) codes. Moreover, we show that our method can be used to solve cooperative data exchange problems with weighted cost as well as the so-called successive local omniscience problem.Comment: 21 pages, 1 figur

Vertical Relations Between Firms and Innovation: An Empirical Investigation of German Firms

The surge in interfirm cooperative agreements can be seen as expressing a way for firms to respond to and to organize market failure, especially in technology markets. The incentives of firms to internalize activities are to avoid the disadvantages, or capitalize on the advantages, of imperfections or disequilibria in external mechanisms of resource allocations. The purpose of this paper is to investigate empirically the occurrence and importance of different modes of vertical relations between innovating firms, suppliers and users, using data from Germany. The analysis is based on a survey conducted by the "Center for European Economic Research" (Mannheim, Germany) among 3122 firms representing 378 different lines of business, mainly in the manufacturing sector. The main results can be summarized as follows: ? 84 % of all innovating firms responded that they have had R&D cooperation agreements with either suppliers or customers or both. This percentage is even higher (99 %) if we consider only those innovating firms that have also had formal R&D departments. The phenomenon of vertical R&D cooperation is therefore widespread among German firms. ? Informal exchange of technical knowledge was perceived as the most important mode of R&D cooperation between innovating firms on one hand and customers and suppliers on the other, followed by formal methods of cooperation such as joint development teams and contractual R&D cooperation. Joint ventures and direct R&D orders to either customers or suppliers were seen as the least important modes of vertical cooperation. ? The occurrence and importance of cooperative agreements between innovating firms, users and input suppliers vary across industries. ? Results of multivariate statistical analysis (correlation, principal components and cluster analysis) suggested that the various modes of R&D cooperation between innovating firms on one hand and customers and suppliers on the other could be reduced to two subgroups: the first one includes formal modes of cooperation, the second one includes only informal exchange of technical knowledge. On this basis patterns of cooperative agreements could be established for firms operating in different industries and for firms using different product and process technologies. --

PROJECT FOR THE ANALYSIS OF LAND TENURE AND AGRICULTURAL PRODUCTIVITY IN THE REPUBLIC OF MACEDONIA

The paper arises out of the Land Market Project and covers detailed data at the individual farm level and in-depth analyses of legal and historical processes. The agricultural sector in Macedonia is characterized by two very different farm enterprise types: small family farms operating on privately owned land, and large socially owned farms. About 30 percent of the total arable land in Macedonia belongs to socially owned farms. Most of the balance belong to the private farm sector; the cooperative sector occupies a small percentage of the arable land. The Land Markets Project addressed five tasks during the six-month term of the project: (1) assess the appropriateness of legislation, regulations, and institutions affecting land tenure and land use, (2) document and assess the land-related constraints to increased productivity and profitability of private farms, (3) document and assess the land-related constraints to increased productivity and profitability of socially owned farms, (4) propose land policy adjustments that would promote increased productivity and profitability of the agricultural sector, (5) identify financial and technical assistance to support the development of land markets that promote efficient, sustainable, and equitable increases in agricultural incomes. This paper reports the results of the first three tasks and then presents a comparative review of the land tenure and productivity results for both the private and the social sector. This comparison forms a basis for policy dialogue. The paper also includes a comprehensive discussion of the policy recommendations that stem from the Land Markets Project.Land tenure--Macedonia (Republic), Land use, Rural--Economic aspects--Macedonia (Republic), Farms, Size of--Macedonia (Republic), Agriculture--Economic aspects--Macedonia (Republic), Agricultural productivity--Macedonia (Republic), Land markets--Macedonia (Republic), Agrarian structure--Macedonia (Republic), Land Economics/Use, Productivity Analysis,

Geographical and Multi-product Linkages of Markets: Impact on Firm Equilibrium Interactions (Some Evidence from the European Car Market)

This paper aims to study geographical and multi-product linkages of markets (multiple market presence) and firm behaviour interdependence as a result of such linkages existence. In particular, it attempts to answer whether the multimarket linkages lead to more cooperative behaviour among the firms, which results in higher prices and profits, and whether the degree of collusive/cooperative behaviour varies across markets. These issues are investigated within a structural oligopoly model for differentiated products for the European automobile market on the basis of the aggregate product-level data for 1970-1999. The results of the study reveal weak (quantitative) effect of multimarket contact on market conduct/pricing in the European car market as well as provide some evidence on the redistribution of the market power from the more collusive to the more competitive markets due to multimarket contact. --multimarket contact,collusion,automobile industry,test for non-nested hypothesis,menu test,structural oligopoly models

Private trader response to market liberalization in Tanzania's cashew nut industry

Between World War II and the early 1970s, Tanzania developed one of the world's largest cashew nut industries. In 1973-74, marketed production reached 145,000 tons (about 30 percent of world production), with cashews providing an important source of income to some 250,000 farmers and being the country's fourth largest source of foreign exchange. This trade was originally developed and organized by private traders (of Indian and Arab origin), although in the 1960s a multitiered marketing system - involving local cooperative societies, regional cooperative unions, and a marketing board - was imposed, with private traders gradually removed from the market system. Despite a buoyant international market, Tanzania's cashew nut industry underwent a steady and massive decline through the 1970s and 1980s. The author examines the factors that contribute to this downward spin: Tanzania's village program, a decline in real producer prices, and inefficiencies in cooperative and marketing board crop collection and downstream activities. With the decline in production, living standards in the main cashew-growing regions worsened, and most of the large-scale, donor-funded, government-owned processing factories became"white elephants."With the industry on the brink of collapse, in 1991 the government announced the liberalization of the cashew nut market, permitting private firms to once again buy and sell the nuts. According to the author, the reform process has been characterized by confusion, uncertainty, and latent government controls and interventions, though the industry shows some signs of recovery. Based on a recent survey, the author examines the liberalization process - including its implementation at the national and local levels, the private sector response to renewed trading opportunities, and the resultant patterns of competition, price discovery, and marketing channel formation. The liberalization experience in Tanzania's cashew nut industry offers interesting insights for other sub-Saharan African countries where uncertainty remains about the appropriate roles (if any) for marketing boards in liberalized markets, about the ability of cooperatives to compete in such markets, and about the ability of indigenous firms to take advantage of new trading opportunities. In Tanzania, neither the cooperatives nor the marketing board have fared well in the liberalized market. Although a relatively large number of private traders have recently entered into cashew buying and selling, successful entry into export marketing has proven viable only for a small number of companies. Their characteristics: medium to large in scale, diversified across commodities, involved in trading and agroindustry, not indigenous, and with strong financial and trading links abroad.Food&Beverage Industry,Environmental Economics&Policies,Economic Theory&Research,Crops&Crop Management Systems,Agricultural Knowledge&Information Systems

Distortions to Agricultural Incentives in Uganda

Distorted incentives, agricultural and trade policy reforms, national agricultural development, Agricultural and Food Policy, International Relations/Trade, F13, F14, Q17, Q18,

The Effect of Capital Requirement Regulation on the Transmission of Monetary Policy: Evidence from Austria.

This paper investigates the existence of a bank lending and a bank capital channel in Austria by applying the dynamic Arellano-Bond GMM-estimator to a quarterly bank level dataset spanning from 1997 to 2003. While we do find evidence that the bank lending channel is in existence, with an important role active for capitalization, we are unable to confirm that the bank capital channel is in force in Austria. Our results indicate some counter-cyclicality in lending activity, a finding that is in line with the existing Austrian literature. Classification-