6,024 research outputs found
Weed management in grain legumes using an intercropping approach
Grain legumes benefit the farming system via symbiotic N2 fixation and subsequent residue incorporation contributing to soil fertility together with their effect as break-crop in cereal rich rotations. However, grain legumes are weak competitors towards weeds and consequently weeds constitute a major problem. Since the European policies for reducing the negative effects of agricultural plant production on the environment point to reductions in pesticide use (Mortensen et al., 2000), there is a requirement to further develop strategies to reduce weeds. Intercropping involves the simultaneous growing of several plant species in the same field and the cropping strategy is known to involve interspecific interferences increasing the use of plant growth resources in space and time (Ofori and Stern, 1987) improving crop competitive ability towards weeds (Hauggaard-Nielsen et al., 2001). The main objectives of the present study was to determine the effects of grainlegume-cereal intercropping on the weed biomass production as compared to the respective sole crops using successive harvests in a three-year field study
The Purchase by Railroads of Their Own Obligations
Recent studies from several authors show that it is possible to lower the fuel consumption for heavy trucks by utilizing information about the road topography ahead of the vehicle. The approach in these studies is receding horizon control where horizon length and residual cost are main topics. To approach these topics, fuel equivalents previously introduced based on physical intuition are given a mathematical interpretation in terms of Lagrange multipliers. Measures for the suboptimality, caused by the truncated horizon and the residual cost approximation, are defined and evaluated for different routes and parameters.Original Publication: Erik Hellström, Jan Åslund and Lars Nielsen, Horizon length and fuel equivalents for fuel-optimal look-ahead control, 2010, 6th IFAC Symposium Advances in Automatic Control. Copyright: INTERNATIONAL FEDERATION OF AUTOMATIC CONTROL IFAC.</p
The effect of CSR performance on firm value across global emerging markets
Drawing on institutional and transaction cost theory and the resource-based view of CSR, I posit that CSR performance across global emerging market companies is positively related to firm valuation. Using an unbalanced panel data approach for a sample with 3,800 firm-year observations representing 657 individual firms from 20 different countries that are classified as emerging markets according to the MSCI EM index during 2010-2016, I find that CSR performance, proxied by the average of the environmental and social pillar scores of the Thomson Reuters EIKON ESG rating database, positively relates to firm valuation, proxied by one-year ahead Tobin’s q (TOBQ). Specifically, a one-standard-deviation increase in normalised CSR performance is – on average – associated with a 0.042-point increase in TOBQ. Compared to the mean value of 1.661 for TOBQ across the sample, this increase constitutes an economically significant share of around 2.5% of that value. This value-enhancing effect of CSR is driven by companies in Asia, while it is absent for companies located in EMEA and more pronounced for companies of the Americas. Additional analyses further reveal that while overall Thomson Reuters corporate governance score performance is positively related to firm valuation, the way in which these scores are constructed seems to fail to reflect important differences in the governance environment of emerging market companies compared to their developed market counterparts. Moreover, the number of sell-side analysts covering the stock of these companies is (next to CSR) positively related to firm valuation but has a mitigating effect on the positive relation between CSR performance and firm valuation
Equity-Linked Pension Schemes with Guarantees
This paper analyses the relationship between the level of a return guarantee in an equity-linked pension scheme and the proportion of an investor's contribution needed to finance this guarantee. Three types of schemes are considered: investment guarantee, contribution guarantee and participation surplus. The evaluation of each scheme involves pricing an Asian option, for which relatively tight upper and lower bounds can be calculated in a numerically efficient manner. We find a negative (and for two contracts pecifications also concave) relationship between the participation in the surplus return of the investment strategy and the guarantee level in terms of a minimum rate of return. Furthermore, the introduction of a possibility of early termination of the contract (e.g. due to the death of the investor) has no qualitative and very little quantitative impact on this relationship.pension funds; forward risk adjusted measure; Asian option
Population ageing, public debt and sustainable fiscal policy
Due to rising life expectancy and declining fertility, the world’s population is ageing rapidly. Not only does the number of elderly relative to the number of working-age people increase, so does the proportion of the very old in the general population of the aged. In consequence, government spending on pensions, health care and other services provided for the aged is increasing and has been projected to rise on an even larger scale after the turn of the century. How can the old-age social expenditures be accommodated into a sustainable path for the general government budget?2 In most European countries, public outlays allocated to the elderly are financed on a pay-as-you-go (PAYG) basis, i.e. benefits paid to retired people are directly financed by contemporaneous taxes levied on workers. In periods with dramatic swings in the age structure, the tax rate is likely to swing as well. For example, when the population is ageing, the ratio of the number of persons of drawing age to that of those of contributing age increases, and PAYG financing implies an increase in the transfers from young to old. Does that cause generational conflicts, and will the PAYG scheme eventually be undermined?
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