Special Data Section Domestic Debt Markets in Sub-Saharan Africa

This study discusses the role of domestic debt markets in sub-Saharan Africa (SSA) based on a new data set covering 27 SSA countries during the 20-year period 1980-2000. The study finds that domestic debt markets in these countries are generally small, highly short term, and often have a narrow investor base. Domestic interest payments present a significant burden to the budget, despite much smaller domestic than foreign indebtedness. The use of domestic debt is also found to have significantly crowded out private sector lending. Finally, the study identifies significant differences among the size, cost, and maturity structure of domestic debt markets in heavily indebted poor countries (HIPCs) and non-HIPCs. Copyright 2005, International Monetary Fund

Explicit constructions and properties of generalized shift-invariant systems in L2(R)L^2(\mathbb{R})

Generalized shift-invariant (GSI) systems, originally introduced by Hern\'andez, Labate & Weiss and Ron & Shen, provide a common frame work for analysis of Gabor systems, wavelet systems, wave packet systems, and other types of structured function systems. In this paper we analyze three important aspects of such systems. First, in contrast to the known cases of Gabor frames and wavelet frames, we show that for a GSI system forming a frame, the Calder\'on sum is not necessarily bounded by the lower frame bound. We identify a technical condition implying that the Calder\'on sum is bounded by the lower frame bound and show that under a weak assumption the condition is equivalent with the local integrability condition introduced by Hern\'andez et al. Second, we provide explicit and general constructions of frames and dual pairs of frames having the GSI-structure. In particular, the setup applies to wave packet systems and in contrast to the constructions in the literature, these constructions are not based on characteristic functions in the Fourier domain. Third, our results provide insight into the local integrability condition (LIC).Comment: Adv. Comput. Math., to appea

NORDIC MOBILITY COIN: En incitamentsmodel for grøn mobilitet

Nordic Mobility Coin is a mobility platform with an incentive model that rewards users who walk, take the bike or share transportation. A holistic mobility concept that expands the concept of transport to cover the entire journey, whether is through shared mobility such as car-pooling or mass transport, biking and walking.  The incentive platform will allow users to obtain a Nordic Mobility currency that can be used within different mobility sectors across Scandinavia. By gathering ‘mobility coins’ through walking, biking or taking the public transport, the user can use these coins to acquire rebates towards future transportation trips. For example, a person chooses to bike to the local train station, collect a cheaper train ride, and walk the remaining way to the office, and earn even more coins for the next trip. Or even better, a person bikes the entire journey and collects cheaper or even free tickets for use on public transport later. In suburban and rural areas with weaker coverage of public transport the platform will also reward shared cars, carpooling and even hitchhiking.  The platform will use the concept of nudging and gamification, to be in line with how other commercial actors are building successful platforms. By allowing people to gather coins that can have financial value, we allow for the possibility of gamification that has proven to be successful when trying to achieve behavioral change.  The impact of sustainable mobility reaches way beyond the scope of mobility. There have been numerous calculations of the societal cost connected to congestion, negative environmental impact, health, hazardous air quality, as well as the positive health benefits from walking and cycling etc.  Ruter’s (Oslo- Akershus public transport) socio economic report suggests that for every 1 NOK that is invested in public transport (the report includes biking and walking together with public transport offerings) society receives 4.5 NOK in return. Therefore, it makes sense to create novel way of incentivizing and instantaneously rewarding citizens that contribute to society by choosing the most appropriate sustainable transport at any given time.  With that in mind, the incentive system could go beyond public transport and include other brands and products that are supporting the underlaying vision of green mobility. One example could be a person who now walks to work might be able to collect enough coins to get a rebate on new sneakers, the gym or the cinema. For actors within the public sector, the incentives are a higher modal share of public transportation, with its positive environmental side effects, while for the commercial actors, this could be seen a corporate social responsibility project, where the rebates they offer create both commercial gains while they contribute towards a better future.&nbsp

Hvad koster forsinkelser af godstransporten?

Hvad koster det virksomhederne, når transporten af varer forsinkes? Og i hvor høj grad indgår omkostningerne ved forsinkelser, når der regnes på de samfundsøkonomiske perspektiver ved nye infrastrukturprojekter? Dette har DI og Rambøll undersøgt ved hjælp af en række interviews med både transportvirksomheder og transporttunge virksomheder og en survey blandt handels-, fremstillings- samt bygge- og anlægsvirksomheder. De deltagende virksomheder er blevet spurgt om betydningen af transport og pålidelighed, omfanget og konsekvenserne af forsinkelser samt hvad de gør for at minimere risikoen for forsinkelser. Der er gennemført 36 dybdegående interviews og 670 virksomheder har deltaget i surveyen. Både interviews og surveyresultater viser, at der er stor forskel på, hvilke omkostninger der er forbundet med forsinkelser afhængigt af virksomheden og den konkrete transport. De fleste virksomheder har både indgående leverancer af råmaterialer, halvfabrikata og færdigvarer mv. og udgående leverancer til kunder. I surveyen er der sondret mellem ind- og udgående leverancer. Der er generelt ikke den store forskel på, hvor vigtigt det er for virksomhederne, at henholdsvis ind- og udgående leverancer ankommer som aftalt. Andelen er leverancer, der forsinkes på grund af trængsel, er også nogenlunde den samme for ind- og udgående leverancer. Der kan være forskel på, hvilke konsekvenser det har for virksomhederne, når leverancer forsinkes – afhængigt af om der er tale om ind- eller udgående leverancer. Når indgående leverancer forsinkes, kan det eksempelvis have konsekvenser for produktionen. I surveyen svarer mere end halvdelen af virksomhederne, at forsinkede indgående leverancer inden for det seneste år har medført produktionstilpasninger, og hos mere end hver tredje virksomhed har forsinkede indgående leverancer medført produktionsstop. Mere end to ud af tre virksomheder har det seneste år haft øget administrativt arbejde på grund af forsinkede indgående leverancer, mens knap to tredjedel har haft øgede logistikomkostninger. Det har også konsekvenser for virksomhederne, når udgående leverancer forsinkes. Hos tre ud af fire virksomheder har det ført til øget administrativt arbejde, og knap hver fjerde virksomhed er inden for det seneste år blevet mødt med et krav om betaling af bod på grund af forsinkede leverancer. Mange virksomheder arbejder målrettet for at minimere både risikoen for forsinkelser og konsekvenserne af eventuelle forsinkelser. Mere end en tredjedel af virksomhederne sender varerne af sted i god tid, og 25- 30 pct. har større sikkerhedslagre. Ca. 10 pct. af virksomhederne bestiller kørsel om natten, hvor der er mindre trængsel. Øgede administrative omkostninger, sikkerhedslagre og øgede produktionsomkostninger er eksempler på omkostninger, som ikke indgår i en klassisk samfundsøkonomisk beregning. I analysen har det ikke været muligt at estimere størrelsen på de forskellige ikke-inkluderede omkostninger. Når politikerne fremover skal træffe beslutninger om investeringer i trafikal infrastruktur, er det vigtigt, at det i beslutningsgrundlagene afspejles, hvad det reelt koster erhvervslivet, når transporter forsinkes. Der er således behov for, at der arbejdes videre med at kvantificere en række af de omkostninger, som i dag ikke indgår i samfundsøkonomiske analyser af nye infrastrukturprojekter

Improving 1D Stellar Models with 3D Atmospheres

Stellar evolution codes play a major role in present-day astrophysics, yet they share common issues. In this work we seek to remedy some of those by the use of results from realistic and highly detailed 3D hydrodynamical simulations of stellar atmospheres. We have implemented a new temperature stratification extracted directly from the 3D simulations into the Garching Stellar Evolution Code to replace the simplified atmosphere normally used. Secondly, we have implemented the use of a variable mixing-length parameter, which changes as a function of the stellar surface gravity and temperature -- also derived from the 3D simulations. Furthermore, to make our models consistent, we have calculated new opacity tables to match the atmospheric simulations. Here, we present the modified code and initial results on stellar evolution using it.Comment: 4 pages, 5 figures; submitted to the conference proceedings: Seismology of the Sun and the Distant Stars 201

Application of processed organic municipal solid waste on agricultural land - a scenario analysis

Source separation, composting and anaerobic digestion, with associated land application, are increasingly being considered as alternative waste management strategies to landfilling and incineration of municipal solid waste (MSW). Environmental life cycle assessments are a useful tool in political decision-making about waste management strategies. However, due to the diversity of processed organic MSW and the situations in which it can be applied, the environmental impacts of land application are very hard to determine by experimental means. In the current study, we used the agroecosystem model Daisy to simulate a range of different scenarios representing different geographical areas, farm and soil types under Danish conditions and legislation. Generally, the application of processed organic MSW resulted in increased emissions compared with the corresponding standard scenarios, but with large differences between scenarios. Emission coefficients for nitrogen leaching to the groundwater ranged from 0.03 to 0.87, while those for nitrogen lost to surface waters through tile drains ranged from 0 to 0.30. Emission coefficients for N2O formation ranged from 0.013 to 0.022 and for ammonia volatilization from 0.016 to 0.11. These estimates are within reasonable range of observed values under similar conditions. Furthermore, a sensitivity analysis showed that the estimates were not very sensitive to the mineralization dynamics of the processed organic MSW. The results show that agroecosystem models can be powerful tools to estimate the environmental impacts of land application of processed MSW under different conditions. Despite this, agroecosystem models have only been used to a very limited degree for this purpose