Public Good Menus and Feature Complementarity

The distance metric on the location space for multidimensional public good varieties represents complementarity between the goods features. "Euclidean" feature complementarity has atypical strong properties that lead to a failure of intuition about the optimal-menu design problem. If the population is heterogeneous, increasing the distance between two varieties is welfare-improving in Euclidean space, but not generally. A basic optimal-direction principle always applies: "anticonvex" menu changes increase participation and surplus. A menu replacement is anticonvex if it moves the varieties apart in the common line space. The result extends to some impure public goods with break-even pricing and variety-specic costs. A sufficient condition for menus to be Pareto-optimal is that "personal price" (nominal price plus perceived distance from a variety) is linear in the norm that induces the distance metric.Public Good Menus; complementarity

Can Rivalry Increase Prices?

Spatially differentiated duopolists set higher-than-monopoly prices at some distances. This phenomenon is shown to occur in any finite- dimensional space for a class of reservation prices that covers concavity and convexity in perceived distance from a design. But an upper bound on the equilibrium duopoly price converges monotonically and quickly to the monopoly price in dimensionality. If consumers care about sufficiently many features of the product (a very small number of criteria is enough), monopoly nearly leads to an extreme price.price effect of competition, multidimensional product spaces, duopoly pricing, spatial competition

Good and Bad Consistency in Regulatory Decisions

We examine sources of consistent regulatory decisions in a model where regulators respond to mixed incentives, including career concerns. In the reference case, regulators act as "public servants" who strive to make the socially optimal decision, given limited information and the opportunity to observe the prior decision of another regulator. Adding career concerns, such as a desire to avoid controversy or to implement a future employer’s preferred policy, tends to reduce the degree of differentiation in sequentially taken decisions, hence increasing consistency. Thus, it is possible to observe that the self-interested career concerns of regulators give rise to consistency in regulatory decision-making. This type of consistency might lead to substantial deviations from optimal regulatory policies.

Is More Entrepreneurship better?

We develop a new perspective on the boundary of the firm that is consistent with the empirical observation that the share of entrepreneurs first decreases and then increases in the course of economic development. Existing theory based on transaction costs is difficult to relate to these well-established dynamics. Our approach focuses on changing incentives to specialize and adapt, in order to access complementarities that arise from diverse abilities and access to wealth. We discuss why the efficient number of entrepreneurs is bounded and changes in the course of economic development

Firm Formation with Complementarities: The Role of the Entrepreneur

We model the emergence of organization forms in a game between prospective entrepreneurs. Complementary roles arise endogenously in a way that admits a stable assignment of workers to firms. This contrasts with existing work on job matching, where stability typically requires workers to be substitutes. Our approach demonstrates that the labor market selection of entrepreneurs and their profit-maximizing choices lead to specific technologies in which certain workers are substitutes and others are complements. We give a simple characterization of equilibrium firm memberships and organizations. We show that payoffs in our non-cooperative solution lie in the core of the corresponding cooperative game, and can be obtained in a decentralized process that reduces information and planning requirements for the entrepreneur

Entrepreneurship and Organization Design

We model entrepreneurship and the emergence of rms as an out- come of simultaneous bidding for labor services among heterogeneous agents. What distinguishes our approach from prior work is that oc- cupational choice and job matching are determined simultaneously, so that the opportunity costs of entrepreneurs are accounted for. Those who are relatively unmanageable, while possibly excellent managers themselves, become entrepreneurs. Entrepreneurs compete and create value by building e¢ cient organizations and o¤ering potentially well- paid jobs to others. While the entry of an additional entrepreneur typically reduces some individual wages, we show that it always raises the average wage and depresses the average income of incumbent en- trepreneurs. This result may help explain the empirically low returns to entrepreneurship

Entrepreneurship, firm creation, and organizational design

We model the emergence of organization forms in simultaneous bidding for labor services among heterogeneous agents. What distin- guishes our approach from prior work is that occupational choice and job matching are determined simultaneously, so that the opportunity costs of entrepreneurs are accounted for. Equilibrium rms are diverse in size and organization; workers turn out endogenously to be com- plements or substitutes. The organization designs are e¢ cient and maximize complementarity between agents

Flow paths and variability of the North Atlantic Current: A comparison of observations and a high-resolution model

The North Atlantic Current (NAC) is subject to variability on multiannual to decadal time scales, influencing the transport of volume, heat, and freshwater from the subtropical to the eastern subpolar North Atlantic (NA). Current observational time series are either too short or too episodic to study the processes involved. Here we compare the observed continuous NAC transport time series at the western flank of the Mid-Atlantic Ridge (MAR) and repeat hydrographic measurements at the OVIDE line in the eastern Atlantic with the NAC transport and circulation in the high-resolution (1/20°) ocean model configuration VIKING20 (1960–2008). The modeled baroclinic NAC transport relative to 3400 m (24.5 ± 7.1 Sv) at the MAR is only slightly lower than the observed baroclinic mean of 27.4 ± 4.7 Sv from 1993 to 2008, and extends further north by about 0.5°. In the eastern Atlantic, the western NAC (WNAC) carries the bulk of the transport in the model, while transport estimates based on hydrographic measurements from five repeated sections point to a preference for the eastern NAC (ENAC). The model is able to simulate the main features of the subpolar NA, providing confidence to use the model output to analyze the influence of the North Atlantic Oscillation (NAO). Model based velocity composites reveal an enhanced NAC transport across the MAR of up to 6.7 Sv during positive NAO phases. Most of that signal (5.4 Sv) is added to the ENAC transport, while the transport of the WNAC was independent of the NAO

Synthesis of normal and variant human hypoxanthine-guanine phosphoribosyltransferase in Escherichia coli

Naturally occurring mutations in hypoxanthine-guanine phosphoribosyltransferase (HPRT) have been identified by amino acid sequencing, cDNA cloning, and direct nucleotide sequencing of PCR-amplified transcripts. To determine the effect these mutations have on the catalytic properties of the molecule, knowledge of the three-dimensional structure of HPRT is required. A prerequisite for this, however, is the availability of a large amount of purified product for crystallization and x-ray diffraction analysis. For these reasons we have developed an effective means of producing high levels of human HPRT in Escherichia coli using the expression cassette PCR. By taking advantage of a T7 polymerase/promoter system, we have expressed both normal and variant human hprt sequences in E. coli. The proteins synthesized from these sequences are immunologically and enzymatically active, and are physically indistinguishable from the HPRT in B-lymphoblasts derived from normal and three HPRT-deficient subjects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31002/1/0000677.pd

Acoustic transfer of protein crystals from agarose pedestals to micromeshes for high-throughput screening

An acoustic high-throughput screening method is described for harvesting protein crystals and combining the protein crystals with chemicals such as a fragment library