Valuation equilibria with clubs

This paper considers model worlds in which there is a continuum of individuals who form finite-sized associations to undertake joint activities. We show how, through a suitable choice of commodity space, restrictions on the composition of feasible groups can be incorporated into the specification of the consumption and production sets of the economy. We also show that if there are a finite number of types, then the classical results from the competitive analysis of convex finite-agent economies can be reinterpreted to apply.Consumption (Economics)

Technology Adoption and Growth

Technology change is modeled as the result of decisions of individuals and groups of individuals to adopt more advanced technologies. The structure is calibrated to the U.S. and postwar Japan growth experiences. Using this calibrated structure we explore how large the disparity in the effective tax rates on the returns to adopting technologies must be to account for the huge observed disparity in per capita income across countries. We find that this disparity is not implausibly large.

A unified theory of the evolution of international income levels

This essay develops a theory of the evolution of international income levels. In particular, it augments the Hansen-Prescott theory of economic development with the Parente-Prescott theory of relative efficiencies and shows that the unified theory accounts for the evolution of international income levels over the last millennium. The essence of this unified theory is that a country starts to experience sustained increases in its living standard when production efficiency reaches a critical point. Countries reach this critical level of efficiency at different dates not because they have access to different stocks of knowledge, but rather because they differ in the amount of society-imposed constraints on the technology choices of their citizenry.Income

Monopoly rights: a barrier to riches

Our thesis is that poor countries are poor because they employee arrangements for which the equilibrium outcomes are characterized by inferior technologies being used, and being used inefficiently. In this paper, we analyze the consequences of one such arrangement. In each industry, the arrangement enables a coalition of factor suppliers to be the monopoly seller of its input services to all firms using a particular production process. We find that the inefficiencies associated with this monopoly arrangement can be large. Whereas other studies have found that inefficiencies induced by monopoly are at most a few percent of output, we find that eliminating this monopoly arrangement could well increase output by roughly a factor of 3 without any increase in inputs.Wealth

Spatially Resolved Gas Kinematics within a Lyα\alpha Nebula: Evidence for Large-scale Rotation

We use spatially extended measurements of Ly$\alpha$ as well as less optically thick emission lines from an $\approx$80 kpc Ly$\alpha$ nebula at $z\approx1.67$ to assess the role of resonant scattering and to disentangle kinematic signatures from Ly$\alpha$ radiative transfer effects. We find that the Ly$\alpha$, CIV, HeII, and CIII] emission lines all tell a similar story in this system, and that the kinematics are broadly consistent with large-scale rotation. First, the observed surface brightness profiles are similar in extent in all four lines, strongly favoring a picture in which the Ly$\alpha$ photons are produced in situ instead of being resonantly scattered from a central source. Second, we see low kinematic offsets between Ly$\alpha$ and the less optically thick HeII line ($\sim$100-200 km s$^{-1}$), providing further support for the argument that the Ly$\alpha$ and other emission lines are all being produced within the spatially extended gas. Finally, the full velocity field of the system shows coherent velocity shear in all emission lines: $\approx$500 km s$^{-1}$ over the central $\approx$50 kpc of the nebula. The kinematic profiles are broadly consistent with large-scale rotation in a gas disk that is at least partially stable against collapse. These observations suggest that the Ly$\alpha$ nebula represents accreting material that is illuminated by an offset, hidden AGN or distributed star formation, and that is undergoing rotation in a clumpy and turbulent gas disk. With an implied mass of M(<R=20 kpc)$\sim3\times10^{11}$ $M_{\odot}$, this system may represent the early formation of a large Milky Way mass galaxy or galaxy group.Comment: Accepted to ApJ; 25 pages in emulateapj format; 15 figures, 4 table

Review of Becoming Mrs. Lewis

Review of Patti Callahan, Becoming Mrs. Lewis (Nashville, Tennessee: Thomas Nelson, 2018). 406 pages. $25.99. ISBN 9780785224501

An LED-based Flasher System for VERITAS

We describe a flasher system designed for use in monitoring the gains of the photomultiplier tubes used in the VERITAS gamma-ray telescopes. This system uses blue light-emitting diodes (LEDs) so it can be operated at much higher rates than a traditional laser-based system. Calibration information can be obtained with better statistical precision with reduced loss of observing time. The LEDs are also much less expensive than a laser. The design features of the new system are presented, along with measurements made with a prototype mounted on one of the VERITAS telescopes.Comment: Accepted for publication in Nuclear Instruments and Methods in Physics Research