Oil rents and the tenure of the leaders in Africa

It is often underlined that African oil producing countries are politically unstable as a result of this natural resource. Based on the data relating to the duration in office of 101 heads of States exercises of power of 26 African countries (North Africa and Sub-Saharan Africa), our study finds that: this instability does not appear in the executive branch of the state. Conversly, using survival analysis including non-parametric and parametric estimators, and controlling for many factors which affect the leader's tenure, our results suggest a positive link between oil rents and the duration in office of the leader. While other minerals rents do not appear to have the same effect. An interpretation of these results is that oil has a strategic aspect that other mining products do not have. Hence, no matter what the type of political regime is in country, the international community is tempted to exert fewer pressures for the change of the leader in an oil producing State.Duration models

Pollution Policy and Liberalization of Trade in Environmental Goods

During the Doha Round at the World Trade Organization (WTO), reductions in trade barriers on environmental goods (EG) were put forward as a means of helping developed and developing countries alike deal with current environmental problems. We examine the potential effectiveness of such a strategy in countries that rely on imports for their needs in EG. We point out that liberalizing trade in EG might in fact lead to less stringent environmental regulations, resulting in an actual rise in pollution levels. We then show conditions under which the environmental effectiveness and the welfare improvement objective of this trade reform are compromised.

R&D Delegation in a Duopoly with Spillovers

There is evidence that competing firms delegate R&D to the same independent profit-maximizing laboratory. We draw on this stylized fact to construct a model where two firms in the same industry offer transfer payments in exchange of user-specific R&D services from a common laboratory. Inter-firm and within-laboratory externalities affect the intensity of competition among delegating firms on the intermediate market for technology. Whether competition is relatively soft or tight is reflected by each firm’s transfer payment offers to the laboratory. This in turn determines the laboratory’s capacity to earn profits, R&D outcomes, delegating firms’ profits, and social welfare. We compare the delegated R&D game to two other one where firms (i) cooperatively conduct in-house R&D, and (ii) non-cooperatively choose in-house R&D. The delegated R&D game Pareto dominates the other two games, and the laboratory earns positive profits, only if within-laboratory R&D services are sufficiently complementary, but inter-firm spillovers are sufficiently low. We find no room for policy intervention, because the privately profitable decision to delegate R&D, when the laboratory participates, always benefits consumers.Research and development, externalities, common agency.

Horizontal R and D cooperation and spillovers: evidence from France

We test the theoretical prediction that inter-firm spillovers must necessarily be large for the profit differential between cooperation and non-cooperation in R and D to be monotone increasing with them. By using the French data from the 2002 Community Innovation Survey, we find that spillovers have a significant positive impact on the likelihood that competitors cooperate horizontally in R and D only if these spillovers exceed a threshold. Both the value and the significance of estimates increase with the flow of information firms report receiving from competitors.Cooperation

Self-aligned gallium arsenide heterojunction bipolar transistor using refractory metallisation

Improvements in epitaxial growth and processing technologies have revived a great deal of interest in the heterojunction bipolar transistor (HBT). In this project, AIGaAs/GaAS HBTs have been fabricated using a new self-aligned process which exploits the characteristics of some refractory metals deposited by sputtering to obtain a T-shaped contact structure for the emitter. wet and dry etching techniques were used to fabricate the T-shaped contact. A refractory metallisation system consisting of sequentially sputtered layers of Ge/Mo/Ni was investigated for contacting the emitter of the transistor. After alloying in a thermal furnace at 750°C for 30 minutes in a nitrogen atmOSPhere, a low specific contact resistance of 2 x 10-6 ohm-cm was measured by standard transmission line model (TLM) for measurement of contact resistance. A metallisation system consisting of sequentially evaporated AU/Zn/Au was used for the base and Ni/AuGe/Ni/AU was used for the collector. Alloying with the same condition1 as above gave specific contact re1istances of 1.2 x 10-6 ohm-cm for the base and 8.6 x 10 -6 ohm-cm for the collector. AS an alternative to ion implantation, zinc diffusion was used as an alternative technique to dope the base contact region. The acceptor concentration profile of the diffused region was studied by 'Hall and Stripe' technique and a surface concentration of 1 x 10 20 cm -3 was measured. This highly doped base contact region can be used to achieve low ohmic contact to the base. Results show that for devices designed with similar dimensions for both processes, the new self-aligned process shows a net improvement in the frequency response of the devices (ft= 10.7GHZ and &nax=9.8GHZ for self-aligned and ft=8.0GHZ and for conventional 8um HBT)

R&D in Markets with Network Externalities

We study how network externalities affect research and development (R&D) investments by a non-cooperative duopoly that offers compatible products. We find that multiple R&D equilibria may arise when network externalities are non linear in the number of consumers. The lowest R&D equilibrium corresponds to the case where network externalities are absent. However, even in the presence of network externalities, firms may be trapped in a low-R&D equilibrium where output, and therefore consumers' valuation of the network size, is low. We derive the conditions under which the highest-R&D equilibrium Pareto dominates.Network Externalities

Horizontal R&D Cooperation and Spillovers: Evidence from France

We use the French portion of the 2002 Community Innovation Survey to test how spillovers a®ect the likelihood that ¯rms cooperate in R&D. Unlike most existing empirical studies, our results clearly support well-established theoretical predictions of the industrial organization literature. We find that a firm which benefits from higher spillovers from her rivals is more likely to cooperate horizontally in R&D. Moreover, the impact of incoming spillovers on the likelihood of horizontal R&D cooperation is positive and statistically significant only when they are above a threshold. Both the value, and the precision of the estimates, increase with the information flow which firms report receiving from their competitors.cooperation ; research and development ; spillovers

Compulsory and Voluntary Remittances: Evidence from Child Domestic Workers in Tunisia

Based on a survey we conducted among domestic workers in Tunisia, we find that slightly more than half are younger than 18 years old. Most live with their employer and have their wages remitted directly to their parents. We define such remittances as compulsory as opposed to voluntary, and establish that having more young sisters means a higher likelihood of observing compulsory remittances, but that voluntary remittances increase with the number of young brothers. Parents who own some farm assets, or their house, can extract more compulsory remittances from their daughters than other parents. Older domestic workers face lower compulsory remittances, and voluntarily remit less. Finally, we reject the standard tobit model in favour of a type-2 tobit or Gragg's specification.Domestic Workers, Child Labor, Compulsory and Voluntary Remittances, Tunisia.

Inter-Sectorial Risk Pooling and Wage Distributions

This paper develops a model where two agents in different sectors face uncorrelated income risks and mutually self-insure. We discuss how the rent arising from risk pooling modifies the wage distribution in the sector where the employer behaves as a monopsonist.risk pooling, family transfers