Geographical Spillovers and Growth

One of the main subjects in the theory of economic growth is to explain regional differences among rates of growth. In this paper, we address this issue through the notion of the "underdevelopment trap". Such a trap may be the result of strategic complementarities between investment decisions which generate multiple equilibria. The latter may be Pareto inefficient because of technological externalities. We test our model on international pooled data on the period 1970-90. The econometric analysis shows that economic growth rates depend on regional investment decisions. Moreover, it appears that such regional spillovers are channeled mainly through the physical rather than through the human capital stock.Underdevelopment Traps., Technological Externalities, Strategic Complementarity, growth, Regional Spillovers

Lifshitz tails estimate for the density of states of the Anderson model

We prove an upper bound for the (differentiated) density of states of the Anderson model at the bottom of the spectrum. The density of states is shown to exhibit the same Lifshitz tails upper bound as the integrated density of states

An analysis of the benefits of signal injection for low-speed sensorless control of induction motors

We analyze why low-speed sensorless control of the IM is intrinsically difficult, and what is gained by signal injection. The explanation relies on the control-theoretic concept of observability applied to a general model of the saturated IM. We show that the IM is not observable when the stator speed is zero in the absence of signal injection, but that observability is restored thanks to signal injection and magnetic saturation. The analysis also reveals that existing sensorless algorithms based on signal injection may perform poorly for some IMs under particular operating conditions. The approach is illustrated by simulations and experimental data

Increased Exposure of China to Asymmetric External Shocks: Is Fiscal Federalism an Efficient Answer?

The aim of this paper is to examine whether there is a co-insurance mechanism against provincial aggregate income fluctuations between the Chinese provinces. Our theoretical argument relies on the existence of an efficient allocation of risk between the Chinese provinces. According to this analysis, an institutional arrangement between the provinces allows the perfect smoothing of provincial private consumption. In this case, changes in provincial private consumption depend rather on changes in aggregate Chinese income than on asymmetric changes in provincial income. We test this hypothesis on the 1989-2000 period for 30 Chinese provinces using the GMM estimator. Econometric evidence highlights the weakness of co-insurance mechanisms between the Chinese provinces. First, we reject the hypothesis of perfect insurance. Second, there does not seem to exist a significant, though imperfect, insurance mechanism. Indeed, the provinces’ private consumption reactions are the same either after a shock affecting all the provinces or after an asymmetric shock.China., Fiscal Federalism, Regional Economics Risk Coping, Co-insurance

Increased Exposure of China to Asymmetric External Shocks: Is Fiscal Federalism an Efficient Answer?

The aim of this paper is to examine whether there is a co-insurance mechanism against provincial aggregate income fluctuations between the Chinese provinces. Our theoretical argument relies on the existence of an efficient allocation of risk between the Chinese provinces. According to this analysis, an institutional arrangement between the provinces allows the perfect smoothing of provincial private consumption. In this case, changes in provincial private consumption depend rather on changes in aggregate Chinese income than on asymmetric changes in provincial income. We test this hypothesis on the 1989-2000 period for 30 Chinese provinces using the GMM estimator. Econometric evidence highlights the weakness of co-insurance mechanisms between the Chinese provinces. First, we reject the hypothesis of perfect insurance. Second, there does not seem to exist a significant, though imperfect, insurance mechanism. Indeed, the provinces’ private consumption reactions are the same either after a shock affecting all the provinces or after an asymmetric shock.China., Fiscal Federalism, Regional Economics Risk Coping, Co-insurance

Advances in freight transport demand modelling: an assessment with research perspectives

International audienceNumeric, spatialised models for the simulation of freight transport demand have long been inspired by the models for passenger demand. However, in recent years, specific methods have been developped to represent some aspects that are specific to freight transport, including the relationship between freight transport and logistics, and the specific techniques used to carry merchandises. These recent advances are presented, with a distinction of supply oriented models, demand oriented models, and equilibrium models. assessment oi

Adding virtual measurements by signal injection

We propose a method to "create" a new measurement output by exciting the system with a high-frequency oscillation. This new "virtual" measurement may be useful to facilitate the design of a suitable control law. The approach is especially interesting when the observability from the actual output degenerates at a steady-state regime of interest. The proposed method is based on second-order averaging and is illustrated by simulations on a simple third-order system

Are There Spillover Effects Between Coastal and Non-Coastal Regions in China ?

The evolution of regional policy between the Mao era and the Deng era generated much debate concerning inter-provincial disparities and the trade-off between efficiency and equity. The aim of this paper is to explore the existence of regional growth spillover effects looked for Deng’s policy. Indeed, the main objective was the spread of coastal provinces’ growth onto inland provinces’ growth. After reviewing the theoretical underpinnings of such effects, their existence is tested with panel data, for the period 1981-1998. Moreover, the hypothesis of an equal distribution of these effects over all the inland provinces is also tested. A relative failure to boost development of the western provinces from the coastal provinces’ growth is observed. Hence, it would seen to be an error to wait for spillover effects to be sufficient to reduce disparities between Chinese provinces in the short run.panel data., spillover effects, regions, growth, China

Energy-based modeling of electric motors

We propose a new approach to model electrical machines based on energy considerations and construction symmetries of the motor. We detail the approach on the Permanent-Magnet Synchronous Motor and show that it can be extended to Synchronous Reluctance Motor and Induction Motor. Thanks to this approach we recover the usual models without any tedious computation. We also consider effects due to non-sinusoidal windings or saturation and provide experimental data

The influence of information availability on the choice of destination

We set a framework where an individual has to choose one among a set of spatially distributed activities. The individual knows the price of each activity, as well as the distance to reach it. She has either full or zero information about each activity's quality. Qualities are modeled by i.i.d. random variables. Under the full information regime, the individual knows the realizations of the qualities; while under the no information regime, she only knows the distribution of the qualities. In that case, she can decide either ex ante, or en route, how many activities to patronize. We analyze the impact of information availability on the choice process, on the distance the individual covers, and on the individual's expected utility. In this framework, more information yields longer distance traveled, but also higher utility. We compute the individual's willingness to pay for information. Finally, we show that providing information may decrease the individual's benefit when congestion arises