A Theory of Vertical Fiscal Imbalance

This paper examines how sequential decision-making by two levels of government can result in vertical fiscal imbalances (VFI). Federal-regional transfers serve to equalize the marginal cost of public funds between regions hit by different shocks. The optimal vertical fiscal gap minimizes the efficiency cost of taxation in the federation as a whole. The analysis shows how the existence of vertical fiscal externalities, leading regional governments to overprovide public goods, can induce the federal government to create a VFI by selecting transfers that differ from the optimal fiscal gap. When the federal government can commit to its policies before regional governments select their level of expenditures, the VFI will generally be negative. In the absence of commitment, the equilibrium transfer is unambiguously larger than the optimal fiscal gap, resulting in a positive VFI. In an intertemporal setting, the VFI has implications for the sharing of debt between the federal and regional governments.vertical fiscal imbalance, federal-regional transfers, commitment, fiscal externalities

Education, Productivity and Economic Growth: A Selective Review of the Evidence

We review a selection of the theoretical and empirical literature on human capital and growth that appear to provide the most relevant insights for policy development in the Canadian context. We first focus on the extension of the neo-classical growth model with the inclusion of human capital in an open economy framework, and discuss its empirical applications to the Canadian economy. We also examine other issues such as the returns to education and the distance from the technological frontier, the microeconomic versus macroeconomic return to education, and the quantity versus quality of education. Although the levels of investment in education and the overall quality of the educational system in Canada are fairly high, we argue that the returns of additional investments in post-secondary education could still be substantial since Canada is relatively close to the technology frontier.Human Capital, Growth, Policy, education, technological frontier, education quality,

Commitment and Matching Contributions to Public Goods

This paper studies multi-stage processes of non-cooperative voluntary provision of public goods. In the first stage, one or more players announce contributions that may be conditional on the subsequent contributions of others. In later stages, players choose their own contributions and fulfill any commitments made in the first stage. Equilibrium contributions are characterized under different assumptions about the commitment ability of players, the number of public goods and whether players commit to matching rates or to discrete quantities. We focus on contribution mechanisms that can emerge and be sustainable without a central authority, and that therefore may be particularly relevant for the provision of international public goods. Efficient levels of public goods can be achieved under some circumstances.voluntary provision, matching contributions, commitment, multiple public goods

The Efficiency of Voluntary Pollution Abatement when Countries can Commit

In this paper, we characterize a mechanism for reducing pollution emissions in which countries, acting non-cooperatively, commit to match each others' abatement levels and may subsequently engage in emissions quota trading. The analysis shows that the mechanism leads to efficient outcomes. The level of emissions is efficient, and if the matching abatements process includes a quota trading stage, the marginal benefits of emissions are also equalized across countries. Given the equilibrium matching rates, the initial allocation of emission quotas (before trading) reflects each country's marginal valuation for lower pollution relative to its marginal benefit from emissions. These results hold for any number of countries, in an environment where countries have different abatement technologies and different benefits from emissions, and even if the emissions of countries are imperfect substitutes in each country's damage function. In a dynamic two-period setting, the mechanism achieves both intra-temporal and inter-temporal efficiency. We extend the model by assuming that countries are voluntarily contributing to an international public good, in addition to undertaking pollution abatements, and find that the level of emissions may be efficient even without any matching abatement commitments, and the marginal benefits of emissions may be equalized across countries even without quota trading.voluntary pollution abatement, matching commitments, emissions quota trading

Learning active tactile perception through belief-space control

Robots operating in an open world will encounter novel objects with unknown physical properties, such as mass, friction, or size. These robots will need to sense these properties through interaction prior to performing downstream tasks with the objects. We propose a method that autonomously learns tactile exploration policies by developing a generative world model that is leveraged to 1) estimate the object's physical parameters using a differentiable Bayesian filtering algorithm and 2) develop an exploration policy using an information-gathering model predictive controller. We evaluate our method on three simulated tasks where the goal is to estimate a desired object property (mass, height or toppling height) through physical interaction. We find that our method is able to discover policies that efficiently gather information about the desired property in an intuitive manner. Finally, we validate our method on a real robot system for the height estimation task, where our method is able to successfully learn and execute an information-gathering policy from scratch.Comment: 10 pages + references, 6 figure

Black-spruce-lichen woodlands growth and carbon drawdown potentials as revealed by mature stands

The afforestation of widely distributed boreal open woodlands such as lichen woodlands (LWs) could provide both a restoration of the closed-crown forest structure in the boreal forest and a mitigation measure against global warming. By comparing natural, mature stands of LW with their dense counterparts — black-spruce–feathermoss stands as a plantation surrogate — this study aims to validate the long-term LW growth support capacity for a high tree density and their carbon sequestration potential after afforestation. Our results reveal that the site potential of LWs can be either lower or equivalent to that of dense stands. This finding contradicts the paradigm of systematic lower tree growth in LWs. The site potential of LWs can be assessed by dominant tree volume at 50 years. This study also shows that the CBM-CFS3 model can simulate the conservative net carbon balance of afforested LW, and, as such, can help reduce uncertainties regarding the long-term net carbon drawdown of afforested LWs

3D modeling of the flow and heat transfer during DC casting with a combo bag

The goal of this study is to determine the influence of combo bag on the velocity and temperature fields in the liquid metal pool during the DC casting of aluminum ingots. For this, a 3D finite element solution algorithm is used to compute the flow and heat transfer phenomena. The solution approach is able to deal with high Reynolds number turbulent flows, buoyancy effects and flow through combo bag meshed openings. An isothermal study with turbulence modeling quantifies the effect of the combo bag on the flow and an effective viscosity is determined for the respective flow conditions. The coupled flow and heat transfer during ingot formation are solved for forced convection conditions (no buoyancy) and by including the natural convection terms. it is shown that the flow is driven by the inlet flow rate in the vicinity of the combo bag and by natural convection outside this region.La pr\ue9sente \ue9tude vise \ue0 d\ue9terminer l\u2019influence du panier mixte sur la vitesse et les champs de temp\ue9rature dans le m\ue9tal en fusion pendant le coulage par refroidissement direct de lingots d\u2019aluminium. \uc0 cet effet, on utilise un algorithme 3D de solutions \ue0 \ue9l\ue9ments finis pour calculer l\u2019\ue9coulement et le ph\ue9nom\ue8ne de transfert de chaleur. Cette approche de solution permet de tenir compte des \ue9coulements turbulents \ue0 nombre de Reynolds \ue9lev\ue9, des effets de pouss\ue9e et de l\u2019\ue9coulement au travers des ouvertures du panier mixte. Une \ue9tude isotherme avec mod\ue9lisation de la turbulence permet de quantifier l\u2019effet du panier mixte sur l\u2019\ue9coulement, et une viscosit\ue9 effective est d\ue9termin\ue9e pour les conditions d\u2019\ue9coulement respectives. L\u2019\ue9coulement et le transfert de chaleur coupl\ue9s pendant la formation du lingot sont r\ue9solus pour des conditions de convexion forc\ue9e (pas de pouss\ue9e) et en incluant les termes de convexion naturelle. On a montr\ue9 que l\u2019\ue9coulement est gouvern\ue9 par la vitesse d\u2019\ue9coulement \ue0 l\u2019entr\ue9e du panier mixte et par une convexion naturelle en dehors de cette zone.Peer reviewed: YesNRC publication: Ye

PTP-PEST Couples Membrane Protrusion and Tail Retraction via VAV2 and p190RhoGAP

Cell motility is regulated by a balance between forward protrusion and tail retraction. These phenomena are controlled by a spatial asymmetry in signals at the front and the back of the cell. We show here that the protein-tyrosine phosphatase, PTP-PEST, is required for the coupling of protrusion and retraction during cell migration. PTP-PEST null fibroblasts, which are blocked in migration, exhibit exaggerated protrusions at the leading edge and long, unretracted tails in the rear. This altered morphology is accompanied by changes in the activity of Rho GTPases, Rac1 and RhoA, which mediate protrusion and retraction, respectively. PTP-PEST null cells exhibit enhanced Rac1 activity and decreased RhoA activity. We further show that PTP-PEST directly targets the upstream regulators of Rac1 and RhoA, VAV2 and p190RhoGAP. Moreover, we demonstrate that the activities of VAV2 and p190RhoGAP are regulated by PTP-PEST. Finally, we present evidence indicating the VAV2 can be regulated by integrin-mediated adhesion. These data suggest that PTP-PEST couples protrusion and retraction by acting on VAV2 and p190RhoGAP to reciprocally modulate the activity of Rac1 and RhoA