Dynamical effects induced by long range activation in a nonequilibrium reaction-diffusion system

We both show experimentally and numerically that the time scales separation introduced by long range activation can induce oscillations and excitability in nonequilibrium reaction-diffusion systems that would otherwise only exhibit bistability. Namely, we show that the Chlorite-Tetrathionate reaction, where autocatalytic species diffuses faster than the substrates, the spatial bistability domain in the nonequilibrium phase diagram is extended with oscillatory and excitability domains. A simple model and a more realistic model qualitatively account for the observed behavior. The latter model provides quantitative agreement with the experiments.Comment: 19 pages + 9 figure

Heterogeneity, Job Creation and Unemployment Volatility

In this paper, I explore the impact of match-specific heterogeneity at the job creation margin on business cycle fluctuations. I show that this form of heterogeneity alone does not help to amplify labor market volatility, either under full or under asymmetric information. First, I show analytically that, under full information, heterogeneity has no first-order effect on the response of unemployment and job creation to productivity, and actually tends to dampen the response of market tightness. Then, in a series of calibrations, I show that with both full and asymmetric information, the model delivers labor market volatilities close to the representative-agent, full-information benchmark. Copyright The editors of the "Scandinavian Journal of Economics" 2008 .