A Model-To-Model Analysis of Bertrand Competition

This paper studies a version of the classical Bertrand model in which consumers exhibit some strategic behavior when deciding from what seller they will buy. We use two related but different tools. Both consider a probabilistic learning (or evolutionary) mechanism, and in the two of them consumers\' behavior influences the competition between the sellers. The results obtained show that, in general, developing some sort of loyalty is a good strategy for the buyers as it works in their best interest. First, we consider a learning procedure described by a deterministic dynamic system and, using strong simplifying assumptions, we can produce a description of the behavior of the process. Second, we use finite automata to represent the strategies played by the agents and an adaptive process based on genetic algorithms to simulate the stochastic process of learning. By doing so we can relax some of the strong assumptions used in the first approach and still obtain the same basic results. It is suggested that the limitations of the first approach (analytical) provide a good motivation for the second approach (Agent-Based). Indeed, although both approaches address the same problem, the use of Agent-Based computational techniques allows us to relax hypothesis and overcome the limitations of the analytical approach while obtaining the same basic results.Agent-Based Computational Economics, Model-To-Model Analysis,

Working Paper 10-10 - The long-term adequacy of the Belgian public pension system: An analysis based on the MIDAS model

This working paper describes the second version of MIDAS (an acronym for ‘Microsimulation for the Development of Adequacy and Sustainability'), a dynamic population model with dynamic cross-sectional ageing. This model simulates the life spans of individuals in the base dataset, including with their interactions, for the years between 2003 and 2060. It enables to produce, on that period, adequacy assessment of pensions in Belgium that is coherent with the baseline budgetary projections of the 2009 report of the Study Committee for Ageing realized by the Federal Planning Bureau's semi-aggregated MALTESE model. Indeed, MIDAS aligns its socio-economic and demographic projections and its macro-economic assumptions on the 2009 report of the Study Committee for Ageing. The adequacy of pensions is analysed through the replacement ratio, inequality measures among pensioners and poverty risk indicators of the elderly.Adequacy, Pensions, Microsimulation

Combined Assessment of Future Heat Supply and Demand - A Dynamic Systems Approach

In order to meet climate change mitigation targets, the use of fossil fuels has to be reduced and, eventually, be phased out in all sectors. As the heating sector occupies a central place in energy systems, especially in Nordic countries, it is affected by and affects other energy sectors. The demand for space heating and hot water has traditionally been covered by: district heating (DH) systems, whereby buildings are connected through a grid to power plants; and the installation of individual heating technologies within each building. As there are several heating solutions available, the ways in which heating systems will develop in the future when fossil fuels are phased out depend on several factors, which are currently uncertain.As many components of heating systems have long lifetimes, the investments made in the near future will have long-term impacts on the development of heating systems. It will be important to understand how investments and the dispatch of different components depend on the phasing out of fossil fuels and other factors. Therefore, this thesis aims to investigate how the different parts of heating systems develop under different climate policies, electricity prices and heat load profiles.To investigate heating system development when both the supply and demand sides evolve simultaneously, a dynamic systems approach is used in which an expanding heating system is investigated for several decades in the future and new housing is treated heterogeneously.In this thesis, the TIMES modeling framework is used, and the heating system of Gothenburg is applied as modeling case. The demand side is treated heterogeneously by investigating several types of new housing, which means that the resulting cost-efficient solution may be different for different types of housing. The investment cost for new DH grid connections is therefore assessed for each housing type.The modeling results show that the main effect of a climate policy is decreased investments in new natural gas heat-only boilers (HOBs) in the DH supply side. New natural gas HOBs compete with new large-scale heat pumps (HPs) but does not affect new combined heat and power (CHP) plants. Investments are made in large-scale HPs in the cases of increasing and decreasing electricity prices, whereas no investments are made in biomass CHP plants if the future electricity price decreases.The results further shows that apartment buildings use DH exclusively, while single-family housing with low heat demands and small single-family housing with high heat demand are not connected to the DH system at all. The heating solution for large single-family housing with high heat demands is dictated by both future electricity prices and whether a climate policy is introduced. A heat demand load with a higher relative use during wintertime generally discourages the use of individual HPs.The findings of this thesis may be of interest to city planners and DH utilities, as the findings shows that both the DH supply side and the heating solution for new large single-family housing with high heat demand are affected by climate policy, future electricity prices, and the heat load profile

Working Paper 01-02 - Production and diffusion of ICT in

Information and communication technology (ICT) has become a significant economic activity in most industrialized countries as well as an important engine of innovation and changes in the rest of the economy. It has been recognized as one of the key factors boosting productivity growth and hence business sector competitiveness. Various initiatives have been recently adopted at regional, national and European levels in order to meet quickly the new challenges of ICT use and diffusion in Europe. A growing number of indicators are now available in order to assess the position of each country or region in terms of ICT development and to guide policy decisions in that field. The aim of this report is to provide a clear and succinct view of the relative development of ICT in Belgium by analyzing both the production and the diffusion of ICT in our economy 1 and to highlight the main weaknesses and strengths of the Belgian economy in that area. Even if the sector has been recently characterised by stock markets ups and downs and numerous bankruptcies, production of ICT goods and services has contributed significantly during the nineties to the growth of economic activity and employment in some industrialised countries as for instance in Anglo-saxon and Scandinavian countries. Has Belgian economic activity benefited from the boom in the ICT sector to the same extent as other industrialised countries? What kind of development can be expected in the future? These are the main questions addressed in the part of the report devoted to the analysis of the Belgian ICT production sector.

The Insistence of Inclusion: The Black Excellence Project

During the spring semester of 2020, COVID-19 did not stop this group of determined 9th graders at Bard Early College D.C. Together, they embarked on the Black Excellence Project (“BEP @ Bard”) with the partnership of Amateka College Prep. BEP @ Bard provided literacy-instruction while simultaneously teaching Black Excellence: the teaching of historical and contemporary exemplary Black figures who have impacted Washington, D.C. and raised awareness around topics like racism, social justice, and countering anti-Blackness. Throughout instruction, the students learned about multiple Black professionals from a variety of career pathways as they reflected on questions like, “what does Black Excellence mean to you?,” “who is an example of Black Excellence?,” and “are you for Black Excellence?” The culmination of the project was a published book of students’ essays, which centered their voices, their exciting ideas of professional goals and role models, and their critical thoughts about a world that could be if we all celebrated Black Excellence. Abstract authored by Whitney Banyai-Becker, Scholar Activist

Współczesna ukraińska kultura wizualna w drodze do międzynarodowej przestrzeni kulturowej

The article is devoted to the visual culture of Ukraine since independence. It pays special attention to the trends and phenomena of contemporary Ukrainian visual culture that have entered the context of world culture through recognition on international cultural platforms (competitions, festivals, biennials, etc.). The considerations concern the development of various trends in contemporary Ukrainian art, which use various artistic media: photography, installation, performance and film. In particular, Ukrainian conceptual photography was the most interestingly represented by several generations of photographers of the Kharkiv School, who combined radical bodily imagery and social criticism. The Ukrainian installation is represented by the works of artists of the REP (Revolutionary Experimental Space) group, which is focused on the unity of art and politics and considers artistic creation as a political act. An interesting sub-direction of the installation is the video installation, which delivers an original combination of contemporary Ukrainian artists with site-specific art and artistic means of reflecting on the traumas inflicted on Ukrainian society by the war. The article pays special attention to the development of contemporary Ukrainian cinema. The author demonstrates the connection between the work of contemporary Ukrainian filmmakers and the traditions of Ukrainian poetic cinema. In addition, other trends in Ukrainian cinema are identified: the experimental search for a new film language, the development of documentary cinema, on top of the convergence of fiction and non-fiction artistic languages in the work of contemporary Ukrainian filmmakers. The dominant issues of contemporary Ukrainian films selected for screening at leading European film festivals are identified: inclusiveness, reflection on Ukrainian history, war trauma, psychological rehabilitation of combatants, etc.Artykuł poświęcony jest ukraińskiej kulturze wizualnej od czasu uzyskania niepodległości. Tekst zwraca szczególną uwagę na trendy i zjawiska współczesnej ukraińskiej kultury wizualnej, które weszły w kontekst kultury światowej poprzez zdobycie uznania na międzynarodowych platformach kulturalnych (konkursy, festiwale, biennale itp.). Badany jest rozwój różnych trendów we współczesnej sztuce ukraińskiej, które wykorzystują rozmaite media artystyczne: fotografię, instalację, performance i kino. W szczególności ukraińska fotografia konceptualna była najciekawiej reprezentowana przez kilka pokoleń fotografów szkoły charkowskiej, którzy łączyli w swoich pracach radykalne obrazy ciała z krytyką społeczną. Ukraińską instalację reprezentują prace artystów z grupy REP (Rewolucyjna Przestrzeń Eksperymentalna), która koncentruje się na jedności sztuki i polityki oraz traktuje twórczość artystyczną jako akt polityczny. Interesującym podkierunkiem jest instalacja wideo, będąca oryginalnym połączeniem współczesnych ukraińskich artystów ze sztuką site-specific i odzwierciedlająca traumy zadane ukraińskiemu społeczeństwu przez wojnę. Artykuł zwraca szczególną uwagę na rozwój współczesnego kina ukraińskiego. Pokazuje związek między twórczością współczesnych ukraińskich filmowców a tradycjami ukraińskiego kina poetyckiego. Ponadto zidentyfikowano inne trendy w kinie ukraińskim: eksperymentalne poszukiwanie nowego języka filmowego, rozwój kina dokumentalnego oraz konwergencję artystycznych języków fikcji i non-fiction w twórczości współczesnych ukraińskich filmowców. Zidentyfikowano dominujące tematy współczesnych ukraińskich filmów wybranych do pokazów na wiodących europejskich festiwalach filmowych: inkluzywność, refleksja nad ukraińską historią, trauma wojenna, psychologiczna rehabilitacja bojowników itp

Linear or mixed integer programming in long-term energy systems modeling – A comparative analysis for a local expanding heating system

Most computer models used in energy systems optimization modeling studies are formulated usinglinear equations. However, since linear formulations do not always well reflect real-world conditions,they may not always be adequate as policy and support tools. This is particularly the case for localsystem studies attempting to represent technologies at the individual scale, as in the case for localheating system modeling. Thus, the aim of this paper is to investigate differences in the resultingheating solutions and model solution times for a local expanding heating system. Three differentinvestment cost structures for individual and district heating solutions for the heating of new housingare investigated using linear and mixed integer linear programming. The results show that the use ofdistrict heating is higher for the cost structures that use mixed integer linear programming than it isfor the linear cost structures. This result is attributed mainly to the fact that individual air-to-waterheat pumps benefit from the linear equation formulation due to its high coefficient of performanceduring summertime. This finding is important to consider when modeling local energy systems. Thesolution time is, however, significantly shorter for the linear formulations than for the mixed integerlinear formulations

Communal or individual – Exploring cost-efficient heating of new city-level housing in a systems perspective

As cities expand, new buildings are constructed and they require heating. With increasing integration of the heating and electricity sectors and forecasts of rapid growth in electricity demand, heating choices become critical for the sustainability transition. The main heating options are communal or individual, where the communal option is represented by district heating (DH) and the individual option mainly by heat pumps or biomass heating. Which option is best from the cost perspective depends on the building type and on the energy system development. Thus, this paper investigates cost-efficient heating of new city-level housing in a systems perspective under various scenarios. The investigation was carried out using an energy systems optimization model based on a case representing Swedish conditions. A dynamic approach was used to investigate cost-efficient development of the supply side and demand side simultaneously. The results indicate that the most cost-efficient heating systems are: DH for apartment buildings; and individual heating options for single-family housing with low heat demands. For large single-family housing with high heat demands, the cost-efficient solution depends on the heat demand profile. Higher heat use during winter favors DH and individual biomass boilers, but diminishes the economic feasibility of individual heat pumps