Although standard economics textbooks are seldom interested in production networks, modern economies are more and more based upon suppliers/customers interactions. One can consider entire sectors of the economy as generalised supply chains. We will take this view in the present paper and study...

We here relate the occurrence of extreme market shares, close to either 0 or 100%, in the media industry to a percolation phenomenon across the social network of customers. We further discuss the possibility of observing self-organized criticality when customers and cinema producers adjust their...

The immune system is a complex system of cells and molecules that can provide us with a basic defense against pathogenic organisms. Like the nervous system, the immune system performs pattern recognition tasks, learns and retains a memory of the antigens that it has fought. The immune system...

In this paper we give a theoretical model of buyers' behaviour on a market for a perishable good where no prices are posted. We show that if buyers learn from their own previous experience there is a sharp division between those who learn to be loyal to certain sellers and those who continue to...

In standard economic theory, mechanisms like Adam Smith's "invisible hand" or the Walrasian auctioneer balance aggregate demand and supply and match individuals such that the market clears. Usually, some kind of price adjustment process is assumed without specifying how the implied transactions...

The paper proposes a method that solves the non-monotonic power problem of a family of structural changes in mean tests based on an orthonormal series filtering of the error process before estimating variance of the test statistics. This method yields a consistent estimator for the variance...