Productivity and Economic Growth in Tunisian Agriculture: An Empirical Evidence

This paper analyse the patterns of productivity and economic growth in the Tunisian agriculture during the 19612000. Results indicated that agriculture output growth where high in both the 19611970 and the 19711980 periods but decreased during the 19912000 period. Average output growth exceeded 6% during the 19811990 period, the average output growth during 19912000 had fallen to 4%. Over the whole period, capital was the most important contributor to output growth and labour is considered as the least significant contributor to economic growth. Total factor productivity contribution to output growth decreased from 4.64% in 19611970 to 2.86% in 19711980. In contrast, this contribution increased in 1981-1990 to close the 4.38%. In the last period, namely 1991-2000, TFP decreased. On average, productivity growth increased by less that 3.6% per year. One major source of the low productivity might be the low level of intermediate input use.Production function, Translog, Agriculture, TFP, Tunisia, International Development, Productivity Analysis, C8, O13, O14,

Agricultural sector and economic growth in Tunisia: Evidence from co-integration and error correction mechanism

For the past two decades, Tunisia has been undertaken important structural reforms, which call in most cases for market and trade liberalization (agricultural structural adjustment program, GATT reforms, free trade area with the European Union). The private-led type of growth strategy with less government intervention has culminated these last years into a more rapid economic growth and openness. Within this context, this paper examines the agricultural sector role into the economic growth and its interactions with the other sectors using time-series co-integration techniques. We use annual data from 1961 to 2005 to estimate a VAR model that includes GDP indices of five sectors in Tunisian economy. Empirical results from this study indicate that in the long-run all economic sectors tend to move together (co-integrate). But, in the short-run, the agricultural sector seems to have a limited role as a driving force for the growth of the other sectors of the economy. In addition, growth of the agricultural output may not be conducive directly to non-agricultural economic sector in the short-run.cointegration, economic growth, agricultural sector, Tunisia

Agricultural Sector and Economic Growth in Tunisia: Evidence from Co-integration and Error Correction Mechanism

For the past two decades, Tunisia has been undertaken important structural reforms, which call in most cases for market and trade liberalization (agricultural structural adjustment program, GATT reforms, free trade area with the European Union). The private-led type of growth strategy with less government intervention has culminated these last years into a more rapid economic growth and openness. Within this context, this paper examines the agricultural sector role into the economic growth and its interactions with the other sectors using time-series co-integration techniques. We use annual data from 1961 to 2005 to estimate a VAR model that includes GDP indices of five sectors in Tunisian economy. Empirical results from this study indicate that in the long-run all economic sectors tend to move together (co-integrate). But, in the short-run, the agricultural sector seems to have a limited role as a driving force for the growth of the other sectors of the economy. In addition, growth of the agricultural output may not be conducive directly to non-agricultural economic sector in the short-run.co-integration, economic growth, agricultural sector, Tunisia, International Development, C22, O13, Q18,

Exponential Energy Decay for Damped Klein-Gordon Equation with Nonlinearities of Arbitrary Growth

We derive a uniform exponential decay of the total energy for the nonlinear Klein-Gordon equation with a damping around spatial infinity in the whole space or in the exterior of a star shaped obstacle

Inductive verification of cryptographic protocols based on message algebras - trace and indistinguishability properties

Since 1981, a large variety of formal methods for the analysis of cryptographic protocols has evolved. In particular, the tool-supported inductive method has been applied to many protocols. Despite several improvements, the scope of these and other approaches is basically restricted to the simple enc-dec scenario (decryption reverts encryption) and to standard properties (confidentiality and authentication). In this thesis, we broaden the scope of the inductive method to protocols with algebraically specified cryptographic primitives beyond the simple enc-dec scenario and to indistinguishability properties like resistance against offline testing. We describe an axiomatization of message structures, justified by a rewriting-based model of algebraic equations, to provide complete case distinctions and partial orders thereby allowing for the definition of recursive functions and inductive reasoning. We develop a new proof technique for confidentiality properties based on tests of regular messages. The corresponding recursive functions are provably correct wrt. to an inductively defined attacker model. We introduce generic derivations to express indistinguishability properties. A central theorem then provides necessary and sufficient conditions that can be shown by standard trace properties. The general aspects of our techniques are thoroughly discussed and emphasized, along with two fully worked out real world case studies: PACE and TC-AMP are (to be) used for the German ID cards. To the best of our knowledge TC-AMP is among the most complex algebraically specified protocols that have been formally verified. In particular, we do not know of any approaches that apply formal analysis techniques to comparable cases.Seit 1981 wurden zahlreiche formale Methoden zur Analyse kryptographischer Protokolle entwickelt und erfolgreich angewendet. Trotz vieler Verbesserungen, beschränkt sich der Anwendungsbereich gerade induktiver Verfahren auf das einfache enc-dec Szenario (Entschlüsseln hebt Verschlüsseln ab) und auf Standardeigenschaften (Vertraulichkeit und Authentifizierung). In dieser Arbeit erweitern wir den Anwendungsbereich der werkzeug-unterstützten induktiven Methode auf Protokolle mit algebraisch spezifizierten kryptografischen Primitiven und auf Ununterscheidbarkeitseigenschaften wie die Resistenz gegen Offline-Testen. Eine Axiomatisierung von Nachrichtenstrukturen, abgeleitet aus einem konstruktiven Modell (Termersetzung), liefert die Basis für die Definition rekursiver Funktionen und induktives Schließen (partielle Ordnungen, Fallunterscheidungen). Eine neue Beweistechnik für Vertraulichkeitseigenschaften verwendet rekursive Testfunktionen, die beweisbar korrekt bzgl. eines induktiv definierten Angreifermodells sind. Die Formalisierung von Ununterscheidbarkeitseigenschaften durch generische Ableitungen und ein zentrales Theorem erlauben eine Reduktion auf Trace-Eigenschaften. Die allgemeinen Aspekte unserer Techniken werden zusammen mit zwei vollständig ausgearbeiteten realen Fallstudien, PACE und TC-AMP, diskutiert, die für den deutschen Personalausweis entwickelt wurden. TC-AMP gehört sicher zu den komplexesten algebraisch spezifizierten Protokollen, die formal verifiziert wurden. Insbesondere, sind uns keine Ansätze bekannt, die vergleichbare Fälle behandeln