Latent separability and price variation in the estimation of demand System

The aim of this paper is to overcome the problems caused by insufficient price variation in estimating a large demand system. For that, we propose a new form of Stone-Lewbel (SL) cross section prices developed under latent separability that explore individual specific variation in the composition of the bundles of exclusive goods. The estimation of demand system under latent separability needs the choice of at least one exclusive good per group. We estimate Quadratic Almost Ideal Demand System (QAIDS) under weak and latent separability using traditional aggregate price indices and SL prices. Our empirical analysis is based on fifteen non durable goods of a Tunisian Family Expenditure Survey Data. The results show greater differences among effects price and estimates of price elasticities obtained under weak separability and latent separability using both traditional price indices and SL prices. We obtain higher precision of estimates of own price elasticities using SL prices under latent separability.Latent separability, Weak separability, Demand system, Exclusive goods, Price variation, SL prices

Innovation decision of Tunisian service firms: an empirical analysis

Innovation is widely recognised as a key driver of economic growth and competitiveness. But, some works focus especially on analyzing the determinants and the effects of innovation while distinguishing between its various types (product innovation, process innovation, radical innovation and incremental innovation). The analysis of the determinants is certainly important, but few research efforts testing the way in which firms make the decision to innovate. Based on a sample of 108 Tunisian service firms, the purpose of the paper is to explain the way in which firms make the decision to innovate: simultaneous (one-stage model) or sequential (two-stage model). We find that the two-stage model has a statistically-significant advantage in predicting the innovation. In practice, the sequential model illustrates well the innovation making-decision procedures.Innovation, Decision making, Service sector.

Choix entre diverses spécifications pour l’étude de la demande agrégée des produits agro-alimentaires en Tunisie

Ce texte porte sur la spécification d’un système de demande des produits agro-alimentaires en Tunisie. La structure de marché rattachée à chaque produit étant différente, nous devrons considérer l’estimation de trois types de système de demande : le système mixte, le système classique et le système réciproque. Nous trouverons, à l’aide du test de Hausman, que le système mixte est supérieur aux deux autres du point de vue de la spécification statistique.This paper aims to provide a specification of the demand system for the agro-alimentary products of Tunisia. The difference between the market structure of these products will make us consider the estimation of three different demand systems: the mixed system, the classical system and the reciprocal system. We will test these demand systems with the Hausman test and find that the statistical specification of the mixed one is better

The Topological Quandles up to Four Elements

The finite topological quandles can be represented as $n\times n$ matrices, recently defined by S. Nelson and C. Wong. In this paper, we first study the finite topological quandles and we show how to use these matrices to distinguish all isomorphism classes of finite topological quandles for a given cardinality $n$. As an application, we classify finite topological quandles with up to 4 elements

Export Behaviour and Propensity to Innovate in a Developing Country: The Case of Tunisia

The relation between export behaviour and the propensity to innovate is an important question for a developing economy. This article dedicated to this question through the analysis of the first innovation survey of Tunisian firms. We analyze the relationship between the export behaviour and the innovation propensity of the firms as it can be qualified using econometric estimations (mainly probit models) and non-parametrical regression trees on the results of the first community innovation survey in Tunisia. Our results show that firms that address both the domestic and foreign demands (partial- exporters) have the highest propensity to innovate, and they better benefit from external knowledge sources, as well as a diversified demand. We find that external knowledge sources, internal R&D efforts and some types of cooperative agreements are complementary for product innovations, but the first play an essential role, in the sense that firms must benefit from at least one external knowledge source to attain a significant innovation propensity. We show that innovation behaviour of three subsets of firms are strongly contrasted: pure exporters who only address the foreign demand, pure domestic firms, and partial exporters.Innovation; exports; openness; development; absorptive capacity

Complementarities between organizational changes, R&D activity and technological cooperation for the French manufacturing firms

This article analyzes the determinants of the French companies’ innovation activity while highlighting the importance and the complementarities of the organizational and technological practices’impact. Our results suggest on one hand, that the product or process innovation is determined by the internal and external attributes of the company (size, demand pull and technological class). On the other hand, the complementarities tests between the technological (R&D activity and technological partnership) and organizational practices showed that these strategies are interconnected and that they have complementary effects which call for their simultaneous adoption. Accordingly, to be able to benefit completely from the positive effect of the partnership and the R&D efforts on innovation, they must be accompanied by certain organizational practices related to a good skills management and the implementation of an organizational architecture facilitating the knowledge creation and sharing.innovation, complementarities, technological and organizational competencies

Determinants of the Innovation Propensity in Tunisia: the Central Role of External Knowledge Sources

This article is dedicated to the analysis of the first innovation survey of the Tunisian firms. Starting from basic mechanisms of innovation processes, we test a set of conjectures adapted to a developing country like Tunisia. We analyze the motivation of firms to innovate and the determinants of product and process innovations. Our results show that firms must benefit from external knowledge sources in order to exhibit significant innovation propensities. The large size is also a necessary (but not sufficient) condition for innovation. We also notice that the participation of the State plays an harmful role.Innovation; development; absorptive capacity; learning

Estimated hedonic wage function and value of life in an African country

This paper reports the first study of compensating wage differentials for work-related fatalities in an African country. Using original data from the 2002 Tunisian Caisse nationale de la sécurité sociale, statistically significant compensating wage differentials are found. The implied value of life is $643800 (US$ 2000).Compensating wage differentials; Value of life