On the co-evolution of investment and bargaining norms

Two parties bargaining over a pie whose size is determined by the investment decisions of both. The bargaining rule is sensitive to the investment behavior. If a symmetric investments profile is observed, bargaining proceeds according to the Nash Demand Game; otherwise bargaining proceeds according to the Ultimatum Game. We are interested in the evolutionary emergence of both an efficient investment norm and a bargaining norm. Under some conditions we prove that these norms co-evolve; when this happens they support the efficient investment and the egalitarian distribution of the surplus. In addition, when surplus requires that at least one agent invests, then either both norms co-evolve or no norm evolves.

On Damage Spreading Transitions

We study the damage spreading transition in a generic one-dimensional stochastic cellular automata with two inputs (Domany-Kinzel model) Using an original formalism for the description of the microscopic dynamics of the model, we are able to show analitically that the evolution of the damage between two systems driven by the same noise has the same structure of a directed percolation problem. By means of a mean field approximation, we map the density phase transition into the damage phase transition, obtaining a reliable phase diagram. We extend this analysis to all symmetric cellular automata with two inputs, including the Ising model with heath-bath dynamics.Comment: 12 pages LaTeX, 2 PostScript figures, tar+gzip+u

Control of cellular automata

We study the problem of master-slave synchronization and control of totalistic cellular automata (CA) by putting a fraction of sites of the slave equal to those of the master and finding the distance between both as a function of this fraction. We present three control strategies that exploit local information about the CA, mainly, the number of nonzero Boolean derivatives. When no local information is used, we speak of synchronization. We find the critical properties of control and discuss the best control strategy compared with synchronization

Successful Takeovers without Exclusion

While most takeover models assume atomistic stock-holders, we analyze a single-raider model with finitely many stockholders. Because the raider can always make some stockholders pivotal, he can overcome the free-rider problem identified by Grossman and Hart (1980) and others in atomistics-stockholder models and profitably take over even without exclusion. One might expect that it would be harder for the raider to make stockholders of more widely held firms pivotal and that exclusion would thus become necessary; however, the infinite-stockholder game cannot yield this conclusion. We also consider the limit of the finite-stockholder game and give conditions under which exclusion is unnecessary. Finally, we show that exclusion leads to the possibility of inefficient takeovers.Center for Research on Economic and Social Theory, Department of Economics, University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/100765/1/ECON022.pd

Stock Price Manipulation Through Takeover Bids

The possibility that a takeover bid is designed solely to allow the bidder to drive up the stock price, sell his holdings at the higher price and drop the bid has not been studied nor incorporated into analyses of takeovers. The purpose of this paper is to explore the viability of this type of manipulation and its effects on takeover attempts.Center for Research on Economic and Social Theory, Department of Economics, University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/100754/1/ECON021.pd

Provision of Public Goods: Fully Implementing the Core through Private Contributions

Standard economic intuition would say that private provision of public goods will be inefficient due to free-rider problems. This view is in contrast to the results in the literature on full implementation where it is shown that (under certain conditions) games exist which only have efficient equilibria. The games usually used to demonstrate existence are quite complex and seem “unnatural†possibly leading to the perception that implementation requires a central authority to choose and impose the game. In a simple public goods setting, we show that a very natural game—similar to one often used elsewhere in the literature to model private provision—in fact fully implements the core of this economy in undominated perfect equilibria. More specifically, we consider a complete information economy with one private good and two possible social decisions. Agents voluntarily contribute any non-negative amount of the private good they choose and the social decision is to provide the public good iff contributions are sufficient to pay for it. The contributions are refunded otherwise. The set of undominated perfect equilibrium outcomes of this game is exactly the core of the economy. We give some extensions of this result, discuss the role of perfection and alternative equilibrium notions, and discuss the intuition and implications of the results.Center for Research on Economic and Social Theory, Department of Economics, University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/100743/1/ECON020.pd

Indications for a slow rotator in the Rapid Burster from its thermonuclear bursting behaviour

We perform time-resolved spectroscopy of all the type I bursts from the Rapid Burster (MXB 1730-335) detected with the Rossi X-ray Timing Explorer. Type I bursts are detected at high accretion rates, up to \sim 45% of the Eddington luminosity. We find evidence that bursts lacking the canonical cooling in their time-resolved spectra are, none the less, thermonuclear in nature. The type I bursting rate keeps increasing with the persistent luminosity, well above the threshold at which it is known to abruptly drop in other bursting low-mass X-ray binaries. The only other known source in which the bursting rate keeps increasing over such a large range of mass accretion rates is the 11 Hz pulsar IGR J17480$-$2446. This may indicate a similarly slow spin for the neutron star in the Rapid Burster