Gum arabic production and marketing in Senegal: interlocked transactions and supply chain implications

Interlocked relationships are characterised by traders’ supply of inputs and cash to producers on credit, to be reimbursed at sale time based on pre-defined prices which are often lower than the prevailing market price. The study analyses determinants of choice for interlocking in the gum arabic sector in Senegal and the effect of interlocking on gum production and market participation; gum arabic is a natural exudates of Acacia Senegal trees that grow in the semi-arid lands of Africa. Data from 422 gum producers in Northern and Eastern regions of Senegal are used. About 45percent of respondents are involved into interlocking with village shop-owners or mobile traders. Interlocking has a negative effect on prices received by gum collectors. However, in the absence of effective credit markets, interlocking positively influences market participation and production as found through a two-step Heckman selection model by the provision of market assurance and safety for emergencies.interlocking, contracts, semi-arid lands, market participation, gum arabic, Agribusiness, Crop Production/Industries,

An Examination of the Effects of Parameter Misspecification

It is well-known that Gaussian hedging strategies are robust in the sense that they always lead to a cost process of bounded variation and that a superhedge is possible if upper bounds on the volatility of the relevant processes are available, cf. El Karoui, Jeanblanc-Picque and Shreve (1998) and in particular for applications to fixed income derivatives Dudenhausen, Schlögl and Schlögl (1998). These results crucially depend on the choice of certain ``natural'' hedge instruments which are not always available in the market and fail to hold otherwise. In this paper, the problem of optimally selecting hedging instruments from a given set of traded assets, in particular of zero coupon bonds, is studied. Misspecified hedging strategies lead to a non-vanishing cost process, which in turn depends on the particular choice of instruments. The effect of this choice on the cost process is analyzed. Referring to bond markets, a thorough study of the implications of volatility mismatching is made and explicit results are stated for a broad range of volatility scenarios.Model misspecification, duplication of bonds, volatility mismatch, optimal selection of hedging instruments

Heterogeneous firms and trade costs: a reading of French access to European agro-food market

This article offers a new reading of intra-European trade based on recent developments in new international economics (Melitz, 2003; Chaney, 2008). These models take the heterogeneity of firms into account and offer a micro-economic analysis of the process of selection at work for firms entering markets. An exporting firm has to bear certain specific costs to break into a market, and only sufficiently productive firms are able to do so. Using individual data for French agro-food firms and the distribution of their exports across European markets, this article shows that access conditions to the various European markets are not identical for French firms: the Belgian market would seem to be a natural extension of the French market, whereas the markets of small, distant countries (Austria, Finland or Sweden) are the least accessible. Econometric analysis based on analysis both of the firm selection process and of the value of their exports shows that the standard geographical variables (distance, country size) affecting the single European market still play a major role in the choice of export markets. Results also reveal that there are still remaining trade costs at entry to the different European markets; but these trade frictions don’t matter to all firms in the same way. The higher the firm experience, the lower the impact of trade costs.firm heterogeneity, trade costs, European Integration., International Relations/Trade,

Can VAR models capture regime shifts in asset returns? a long-horizon strategic asset allocation perspective

In the empirical portfolio choice literature it is often invoked that through the choice of predictors that may closely track business cycle conditions and market sentiment, simple Vector Autoregressive (VAR) models could produce optimal strategic portfolio allocations that hedge against the bull and bear dynamics typical of financial markets. However, a distinct literature exists that shows that non-linear econometric frameworks, such as Markov switching, are also natural tools to compute optimal portfolios arising from the existence of good and bad market states. In this paper we examine whether and how simple VARs can produce empirical portfolio rules similar to those obtained under a range of multivariate Markov switching models, by studying the effects of expanding both the order of the VAR and the number/selection of predictor variables included. In a typical stock-bond strategic asset allocation problem on US data, we compute the out-of-sample certainty equivalent returns for a wide range of VARs and compare these measures of performance with those typical of non-linear models that account for bull-bear dynamics and characterize the differences in the implied hedging demands for a long-horizon investor with constant relative risk aversion preferences. We conclude that most (if not all) VARs cannot produce portfolio rules, hedging demands, or out-of-sample performances that approximate those obtained from equally simple non-linear frameworks.Econometric models ; Vector autoregression ; Asset pricing ; Rate of return

Credit rationing, wealth inequality, and allocation of talent.

We provide a simple model of credit rationing with endogenous occupational chioce. Entrepreneurial talent is subject to private information and to screen borrowers banks ask for collateral. The interplay between the labour market and the credit market leads to multiple equilibria in a natural way. The higher is the wage rate, the lower is the collateral needed to discourage less talented agents from borrowing. This allows a greater number of poor but talented agets to become entrepreneurs, thereby increasing labor demand and justifying the wage increase. We discuss the implications of our model for economic policy which are very different from those suggested by models that focus on the credit market only.occupational choice; adverse selection; wealth distribution; credit rationing

Technology Selection and Appropriate Technology

This paper provides a formal model of technology choice by a single region. Case studies have indicated that the technology acquired by LDCs often seem unsuitable, although the criteria for suitability are often unclear. The reasons which are presented for inappropriateness of the selection often rely more on political arguments then economic ones, or treat the recipient country as a passive actor in the whole process. Can a technology actively selected by a recipient country ever by inappropriate, assuming factor cost ratios represent true relative values? A model presented by Evenson and Bingswanger (1978) indicates that a technology developed in one economic or physical environment may be 'appropriate' to a second, very different environment if the second environment can generate a very limited range of technological possibilities on its own. Ranis (1978) has emphasized the importance of information on technological alternatives flowing smoothly and accurately within the system and the need to acquire capacity for adaptive research. Both these approaches recognize the importance of indigenous research capacity, although Ranis accords more emphasis to friction and proper incentives within the system. Barring policy and management problems, their conclusions appear to be that technology choice will be efficient--the appearance of inappropriateness stems from the lack of explicit recognition of the constraints on technology generation in the system. The model presented below builds on the early models of rational technology selection of Evenson- Binswanger and Ranis. It shares common elements with the Evenson-Binswanger model and may be regarded as a generalization of their model. It goes further, however, in several crucial aspects. It allows the extent of both adaptive and independent research to be choice variables in the technology acquisition decision. It allows for selection out of a continuum of technologies which differ in the environments for which they were designed. It allows for limits to the extent to which technologies can be adapted across environments and allows for losses because of incomplete adaption. The public goodnature of research plays a critical role in determining the efficiency of resource allocation as well. The model presented immediately below is couched in terms relating to agricultural technology. A reason for first presenting a model of agricultural technology selection is that many of the conceptual issues possess more intuitive natural interpretations. A second section will consider the impact of market structure on the development of technology, and a third section will broaden the basic model of agricultural technology development to one which encompasses certain types of fixed capital investment. A fourth section discusses testing of the model.Research and Development/Tech Change/Emerging Technologies,

Food choice factors affecting Malaysian green food consumption

In concurrent with the world development, the market and consumers experience the impact that changes their consumption pattern. As food is the basic need for all living creatures, wiseful choice is necessary to sustain healthy life. Nowadays, people are more aware and concerned with their food consumption and tend to opt for green food. Hence, this study was performed to identify the influence of factors on green food choice. The selection of food by consumers was based on Food Choice Questionnaire (FCQ) consisting of nine factors namely sensory appeal, natural content, health, ethical concern, weight control, convenience, familiarity, mood and price. The study was conducted on 600 adult respondents selected through simple random sampling based on areas in Klang Valley. The extent of influence from factors affecting green food choice was determined using multiple regression controlled with socioeconomic characteristic. Apart from the FCQ factors, green food knowledge and attitude were also identified their strength of influence on green food choice. Familiarity (B=.299; p=.001) and weight-control (B=-.269; p=.012) were the only FCQ factors that was found to be significantly affecting green food choice. Attitude towards green food consumption (B=.499; p=.000) and household income (B=.974; p=0.017) were also significant in influencing green food choice. More aggressive promotion on green food must take place towards healthy living

METODE PEMILIHAN MATERIAL TABUNG CNG MENGGUNAKAN METODE PERFORMACE INDEXES

The compressed natural gas (CNG) cylinder pressure vessel become important in NGV fuel driving system because demand in CNG base as increase. The selection of material should be made effectively to reduce cost and to improve properties of the vessel. The choice of material cannot be made independently of the choice of process by which the material is to be formed, assemblied, finished, and otherwise treated. Cost enters, both in the choice of material and in the way the material is processed. Fully metal CNG pressure vessel is cheap but it is the heaviest pressure vessel compare to other materials. Composite has become an alternative material for CNG pressure vessel since it properties can be modified based on market needed. In this paper, the process of material selection for CNG pressure vessel using performance indexes have been analyzed. The result showing that material AA 6061-T6/S-Glass full wrapped has the highest Performance Indexes point Keyword: compressed natural gas, composite, material selection, performance indexes

The Political Red Queen

In ‘The law of selection in the public economy as compared to the market economy’, Professor Francesco Forte (1982) – contemporary doyen of the Scienza delle finanze tradition – extended an invitation to consider the public economy by means of evolutionary principles of selection. Not many replied to Professor Forte’s invitation. This article is a delayed response to the invitation. Through a parallel with a metaphor from Lewis Carroll, it proposes the Political Red Queen hypothesis: politicians work to stay in power by weakening the evolutionary pressure under which they would otherwise naturally operate. A Political Red Queen exerts effort – runs, in the language of Carroll’s original Red Queen metaphor – to make policy, promulgate laws, supply public and merit goods, and so on with the prime objective to survive by reducing the uncertainty linked to maintaining a political role. A Political Red Queen thus works to weaken ‘natural’ political selection. The Political Red Queen hypothesis is shown to hold, mutatis mutandis, for both democratic and non-democratic political environments. It can be viewed as incorporating a positive public choice nexus between politics-as-exchange and politics-as-power

Data Labeling tools for Computer Vision: a Review

Dissertation presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Data ScienceLarge volumes of labeled data are required to train Machine Learning models in order to solve today’s computer vision challenges. The recent exacerbated hype and investment in Data Labeling tools and services has led to many ad-hoc labeling tools. In this review, a detailed comparison between a selection of data labeling tools is framed to ensure the best software choice to holistically optimize the data labeling process in a Computer Vision problem. This analysis is built on multiple domains of features and functionalities related to Computer Vision, Natural Language Processing, Automation, and Quality Assurance, enabling its application to the most prevalent data labeling use cases across the scientific community and global market