Empirical analysis of regional economic performance in Russia : human capital perspective

Having shown the important role of the Russian economy in the ex-USSR region by causality tests, we proceed to empirical analysis of growth and performance of the Russian regions. A dynamic panel data approach enabled us to obtain elasticity coefficients on proxies for convergence, physical capital, labour and innovation. After including human capital in the reformulated model we resolve endogeneity and reverse causality by introducing two instrumental variable approaches. Taking advantage of the Unified State Exam data we managed to successfully endogenize human capital by number (and share) of outperforming students and by the education index. The second approach helped to improve causality between instruments and human capital: the dates of first university foundation and distance to Moscow successfully explains human capital variations due to historical and spatial characteristics of a given region

A Comparison of Numerical Methods used for\ud Finite Element Modelling of Soft Tissue\ud Deformation

Soft tissue deformation is often modelled using incompressible nonlinear elasticity, with solutions computed using the finite element method. There are a range of options available when using the finite element method, in particular, the polynomial degree of the basis functions used for interpolating position and pressure, and the type of element making up the mesh. We investigate the effect of these choices on the accuracy of the computed solution, using a selection of model problems motivated by typical deformations seen in soft tissue modelling. We set up model problems with discontinuous material properties (as is the case for the breast), steeply changing gradients in the body force (as found in contracting cardiac tissue), and discontinuous first derivatives in the solution at the boundary, caused by a discontinuous applied force (as in the breast during mammography). We find that the choice of pressure basis functions are vital in the presence of a material interface, higher-order schemes do not perform as well as may be expected when there are sharp gradients, and in general that it is important to take the expected regularity of the solution into account when choosing a numerical scheme

Introducing willingness-to-pay for noise changes into transport appraisal: an application of benefit transfer.

Numerous research studies have elicited willingness-to-pay values for transport-related noise, however, in many industrialised countries including the UK, noise costs and benefits are still not incorporated into appraisals for most transport projects and policy changes (Odgaard et al, 2005; Grant-Muller et al, 2001). This paper describes the actions recently taken in the UK to address this issue, comprising: primary research based on the city of Birmingham; an international review of willingness-to-pay evidence; development of values using benefit transfers over time and locations; and integration with appraisal methods. Amongst the main findings are: that the willingness-to-pay estimates derived for the UK are broadly comparable with those used in appraisal elsewhere in Europe; that there is a case for a lower threshold at 1 45dB(A)Leq,18hr1 rather than the more conventional 55dB(A); and that values per dB(A) increase with the noise level above this threshold. There are significant issues over the valuation of rail versus road noise, the neglect of non-residential noise and the valuation of high noise levels in different countries. Conclusions are drawn regarding the feasibility of noise valuation based on benefit transfers in the UK and elsewhere, and future research needs in this field are discussed

Urban wage premia, cost of living, and collective bargaining

In this paper, we estimate the urban wage premia (UWP) in Italy, with its economy characterized by the interplay between collective bargaining and spatial heterogeneity in the cost of living. We implement a reduced-form regression analysis using both nominal and real (in temporal and spatial terms) wages. Our dataset for the 2005-2015 period includes, for workers’ characteristics, unique administrative data provided by Italian Social Security Institute and, for the local CPI computation, housing prices collected by Italian Revenue Agency. For employees covered by collective bargaining, we find a zero UWP in nominal terms and a negative and non-negligible UWP in real terms (-5%). To capture the role played by centralized wage settings, we also consider various groups of self-employed workers, who are not covered by national labour agreements, while living in the same locations and enjoying the same amenities as employees. We find that the UWP for self-employed workers are up to 25 times greater than for employees. Moreover, sorting proves more notable in the case of self-employed workers, i.e. the larger UWP provide the higher incentives for high-skilled individuals and better firms to locate in cities. Our findings are confirmed on extending the analysis along the wage distribution

Disorder, pre-stress and non-affinity in polymer 8-chain models

To assess the role of single-chain elasticity, non-affine strain fields and pre-stressed reference states we present and discuss the results of numerical and analytical analyses of modified 8-chain Arruda-Boyce model for cross-linked polymer networks. This class of models has proved highly successful in modeling the finite-strain response of flexible rubbers. We extend it to include the effects of spatial disorder and the associated non-affinity, and use it to assess the validity of replacing the constituent chain's nonlinear elastic response with equivalent linear, Hookean springs. Surprisingly, we find that even in the regime of linear response, the full polymer model gives very different results from its linearized counterpart, even though none of the chains are stretched beyond their linear regime. We demonstrate that this effect is due to the fact that the polymer models are under considerable pre-stress in their ground state. We show that pre-stress strongly suppresses non-affinity in these unit cell models, resulting in a marked stiffening of the bulk response. The effects of pre-stress we discuss may explain why fully affine mechanical models, in many cases, predict the bulk mechanical response of disordered stiff polymer networks so well.Comment: 29 pages, 7 figures. Submitted to J. Mech. Phys. Solid

Self-diffusion in remodelling and growth

Self-diffusion, or the flux of mass of a single species within itself, is viewed as an independent phenomenon amenable to treatment by the introduction of an auxiliary field of diffusion velocities. The theory is shown to be heuristically derivable as a limiting case of that of an ordinary binary mixture