On choice of technique in the Robinson-Solow-Srinivasan model

We report results on the optimal \choice of technique" in a model originally formulated by Robinson, Solow and Srinivasan (henceforth, the RSS model) and further discussed by Okishio and Stiglitz. By viewing this vintage-capital model without discounting as a speci c instance of the general theory of intertemporal resource allocation associated with Brock, Gale and McKenzie, we resolve longstanding conjectures in the form of theorems on the existence and price support of optimal paths, and of conditions suÆcient for the optimality of a policy rst identi ed by Stiglitz. We dispose of the necessity of these conditions in surprisingly simple examples of economies in which (i) an optimal path is periodic, (ii) a path following Stiglitz' policy is bad, and (iii) there is optimal investment in di erent vintages at di erent times. (129 words)

On a uniform turnpike of the third kind in the Robinson-Solow-Srinivasan model

On using McKenzie’s taxonomy of optimal accumulation in the longrun, we report a “uniform turnpike” theorem of the third kind in a model original to Robinson, Solow and Srinivasan (RSS), and further studied by Stiglitz. Our results are presented in the undiscounted, discrete-time setting emphasized in the recent work of Khan-Mitra, and they rely on the importance of strictly concave felicity functions, or alternatively, on the value of a “marginal rate of transformation”, ξσ, from one period to the next not being unity. Our results, despite their specificity, contribute to the methodology of intertemporal optimization theory, as developed in economics by Ramsey, von Neumann and their followers.

A note on convergence of Peck-Shell and Green-Lin mechanisms in the Diamond-Dybvig model

We study the effects of population size in the Peck-Shell analysis of bank runs. We find that a contract featuring equal-treatment for almost all depositors of the same type approximates the optimum. Because the approximation also satisfies Green-Lin incentive constraints, when the planner discloses positions in the queue, welfare in these alternative specifications are sandwiched. Disclosure, however, it is not needed since our approximating contract is not subject to runs.

On uniqueness of equilibrium in the Kyle Model

A longstanding unresolved question is whether the one-period Kyle Model of an informed trader and a noisily informed market maker has an equilibrium that is different from the closed-form solution derived by Kyle (1985). This note advances what is known about this open problem.

Innovation districts: an investigation of the replication of the 22@ Barcelona’s Model in Boston

In 2000, the city of Barcelona launched 22@ Barcelona, dubbed the innovation district. The city sees the project as a means to accelerate Barcelona’s transition toward the knowledge economy. Other cities around the world have since followed the example of Barcelona, building or planning to build their own innovation districts. Boston began to establish its innovation district in 2010. Cities’ ultimate goal for these initiatives is to become more innovative and thus more competitive. Innovative districts are different from technology parks in that they aim to respond to a new economic paradigm in which economic production flows back to cities. The 22@ Barcelona model involves theoretical designs regarding five layers of innovation: economics, urban planning, productive, innovative, and creative. The comparative approach between 22@ Barcelona and Boston’s Innovation District intends to highlight the similarities and differences between those two innovation districts as well as providing a framework to define innovation districts.

A bidimensional model of matching in the marriage market with women labor decision

We construct a frictionless matching model of the marriage market where women have bidimensional attributes, one continuous (income) and the other dichotomous (home ability). Equilibrium in the marriage market determines intrahousehold allocation of resources and female labor participation. Our model is able to predict partial non-assortative matching, with rich men marrying women with low income but high home ability. We then perform numerical exercises to evaluate the impacts of income taxes in individual welfare and find that there is considerable divergence in the female labor participation response to taxes between the short run and the long run.

Signatures of doubly charged Higgs in the SU(3)(L) circle times U(1)(N) model at the CERN LHC

The scalar sector of the simplest version of the 3-3-1 electroweak model is constructed with three Higgs triplets only. We show that a relation involving two of the constants of the model, two vacuum expectation values of the neutral scalars, and the mass of the doubly charged Higgs boson leads to important information concerning the signals of this scalar particle.

Neutral Higgs bosons in the SU(3)(L)circle times U(1)(N) model

The SU(3)(L)circle times U(1)(N) electroweak model predicts new Higgs bosons beyond the one of the standard model. In this work we investigate the signature and production of neutral SU(3)(L)circle times U(1)(N) Higgs bosons in the e(-)e(+) Next Linear Collider and in the CERN Linear Collider . We compute the branching ratios of two of the SU(3)(L)circle times U(1)(N) neutral Higgs bosons and study the possibility to detect them and the Z' extra neutral boson of the model.

Respiratory heat loss in the sheep: a comprehensive model

A model is presented for the respiratory heat loss in sheep, considering both the sensible heat lost by convection (C-R) and the latent heat eliminated by evaporation (E-R). A practical method is described for the estimation of the tidal volume as a function of the respiratory rate. Equations for C-R and E-R are developed and the relative importance of both heat transfer mechanisms is discussed. At air temperatures up to 30 degreesC sheep have the least respiratory heat loss at air vapour pressures above 1.6 kPa. At an ambient temperature of 40 degreesC respiratory loss of sensible heat can be nil; for higher temperatures the transfer by convection is negative and thus heat is gained. Convection is a mechanism of minor importance for the respiratory heat transfer in sheep at environmental temperatures above 30 degreesC. These observations show the importance of respiratory latent heat loss for thermoregulation of sheep in hot climates.

Evaluation of the elevated T-maze as an animal model of anxiety in the mouse

The elevated T-maze has been developed as an animal model of anxiety to generate both conditioned and unconditioned fears in the same rat. This study explores a version of the elevated T-maze fit for mice. Inhibitory (passive) avoidance-conditioned fear-is measured by recording the latency to leave the enclosed arm during three consecutive trials. One-way escape-unconditioned fear-is measured by recording the time to withdraw from open arms. The results showed that mice do not appear to acquire inhibitory avoidance in the standard T-maze, since their latencies to leave enclosed arm did not increase along trials. Nevertheless, the open arms seemed to be aversive for mice, because the latency to leave the enclosed arm after the first trial was lower in a T-maze with the three enclosed arms than in the standard elevated T-maze, In agreement, the exposure of mice to an elevated T-maze without shield, that reduces the perception of openness, increased significantly the latencies to leave the enclosed arm, However, the absence of the shield also increased the time taken to leave the open arms when compared to that recorded in standard T-maze. Systematic observation of behavioral items in the enclosed arm has shown that risk assessment behavior decreases along trials while freezing increases. In the open arms, freezing did not appear to influence the high latency to leave this compartment, since mice spend only about 8% of their time exhibiting this behavior, These results suggest that mice acquire inhibitory avoidance of the open arms by decreasing and increasing time in risk assessment and freezing, respectively, along three consecutive trials, However, one-way escape could not be characterized. Therefore, there are important differences between mice (present results) and rats (previously reported results) in the performance of behavioral tasks in the elevated T-maze. (C) 1999 Elsevier B.V.

Kondo-attractive-Hubbard model for the ordering of local magnetic moments in superconductors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Incommensurate spin-density-wave and metal-insulator transition in the one-dimensional periodic Anderson model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Remarks on charged vortices in the Maxwell-Chern-Simons model

We study vortex-like configuration in Maxwell-Chern-Simons electrodynamics. Attention is paid to the similarity it shares with the Nielsen-Olesen solutions at large distances. A magnetic symmetry between a point-like and an azimuthal-like current in this framework is also pointed out. Furthermore, we address the issue of a neutral spinless particle interacting with a charged vortex, and obtain that the Aharonov-Casher-type phase depends upon mass and distance parameters. (C) 2003 Published by Elsevier B.V.