Economic choices involving pollution, like those concerning common resources, relate to the emergence of cooperation among actors. Since pollution propagates in space, the temporal dynamics of economic choices is coupled to the spatial dynamics of pollution. We start from a simple description of the internal representations of the agents proposed by Arthur and Lane (1993) to describe information contagion. The simultations done in this paper allow us to discuss the maximum price that the agents agree to pay for non-polluting devices as a function of pollution, propagation of information and memory characteristics of the agents. We also characterize the spatio-temporal dynamics of choices, market share and pollution.
Abstract A molecular field theory, taking into account long‐range electrostatic forces is used to study helix–coil transitions of polynucleotides. The theory predicts the existence of hysteresis when the electrostatic interaction parameter is large compared to the thermal energy. The theory is applied to the acid–base titration of poly(A)·2 poly(U).
2014 Nos études expérimentales de diffusion quasi élastique de la lumière par des solutions semi-diluées d'acide polyadénilique mettent en évidence l'existence simultanée de modes rapides semblables à ceux observés avec des chaines flexibles, et de modes lents dont l'existence semble due à la dynamique des chaines de polynucléotides.La variation des coefficients de diffusion en fonction de la concentration donne quelques indications sur l'origine de ces modes.Abstract.2014 Our experimental studies of quasi-elastic light scattering by semi-dilute solutions of polyadenilic acid show the simultaneous existence of rapid modes similar to those observed with flexible chains, and of slow modes the existence of which is due to polynucleotide chain dynamics.The concentration dependence of diffusion coefficients gives some indications about the origin of these modes.
Abstract We report a systematic study of inelastic light scattering for semidilute solutions of poly(adenilic acid). The results are analyzed in terms of a fast and a slow relaxation time. From their dependence on the wave vector and the polymer concentration, we are able to interpret the results in terms of a collective mode for the fast relaxation time at low wave vector, an individual chain motion for the fast time at large wave vector, and structural relaxation for the slow relaxation time.
We report a series of Azbel'-Kaner cyclotron resonance experiments in lead and mercury at wavelengths varying from 9 to 1 mm. We observe that in both metals the electron-phonon relaxation time is frequency dependent ($\ensuremath{\tau}\ensuremath{\propto}{\ensuremath{\omega}}^{\ensuremath{-}2}$ in lead), and that the effective mass increases slightly for the highest frequency in mercury (3 \ifmmode\pm\else\textpm\fi{} 1% at $\ensuremath{\lambda}=1$ mm).
Standard micro-economics concentrate on the description of markets but is seldom interested in production. Several economists discussed the concept of a firm, as opposed to an open labour market where entrepreneurs would recrute workers on the occasion of each business opportunity. Coase \cite{Coase} is one of them, who explains the existence of firms as institution because they reduce the transaction costs with respect to an open labour market. Whatever the rationale proposed by economists to account for the existence of firms, their perspective is based on efficiency and cost analysis. Little attention is paid to the dynamics of emergence and evolution of firms. The aim of the present manuscript is to check the global dynamical properties of a very simple model based on bounded rationality and reinforcement learning.
Workers and managers are localised on a lattice and they choose collaborators on the basis of the success of previous work relations. The choice algorithm is largely inspired rom the observation and modeling of long term customer/sellers relationships observed on perishable goods markets discussed in Weisbuch etal\cite{Weisbuch} and Nadal etal\cite{Nadal}. The model presented here is in no way an alternative to Coase. We describe the build-up of long term relationships which do reduce transaction costs, and we deduce the dynamical properties of networks built from our simple assumptions.
In conclusion, the present model explains the metastability of employment relations in the firm, but something has to be added to it to explain the more efficient workload repartition observed in real firms.
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