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on Regulation |
| By: | SHIMOMURA Mizue; KEELEY Alexander Ryota; MATSUMOTO Ken'ichi; TANAKA Kenta; MANAGI Shunsuke |
| Abstract: | The increase in variable renewable energy (VRE) has brought significant changes in the power system, including a decrease in the average electricity market price owing to the merit order effect (MOE). In this study, we use machine learning and Shapley additive explanation (SHAP) to comprehensively examine the drivers of market price volatility, including the interaction between VRE and demand, fuel prices, and operation capacity in the Japanese electricity market which solar power installation is expanding rapidly. The results of SHAP reveal that there is a large decline effect for market price in solar power during daytime; however, the effect varies depending on the time of day, season, and demand. In addition, the results suggest that the market price increases when demand is high and solar generation is low, such as during summer evenings, which may be because of natural gas generation with higher marginal costs. The study reveals that impact of expanded VRE will not only have the MOE which decreasing average market prices, but may also prompt structural changes in electricity supply, causing market instability and price spikes in the transition process. |
| Date: | 2022–09 |
| URL: | http://d.repec.org/n?u=RePEc:eti:dpaper:22090&r= |
| By: | Jorge Balat; Juan Esteban Carranza; Juan David Martin; Alvaro Riascos |
| Abstract: | We investigate the effects of a change in the regulation of the spot market for electricity in Colombia that took place in 2009. Specifically, the regulation switched from an auction mechanism with simple bids to one with complex bids to allow generators to separately bid on variable and quasi-fixed components. This greater exibility was introduced to reduce production inefficiencies that arise from non-convexities in the cost structures of thermal generators. In this paper, we estimate and compute a structural model to quantify the effects of this change on allocation efficiency along with the effects on the wholesale price of electricity in Colombia. Consistently with previous reduced form evidence, we show that the production efficiency increased under the new dispatch mechanism, but prices increased. ****RESUMEN: En este documento investigamos los efectos de un cambio en la regulación del mercado spot de electricidad en Colombia, que tuvo lugar en 2009. Específicamente, la regulación cambió de un esquema de subastas simples a uno de subastas complejas para permitir a los generadores hacer ofertas separadas de los componentes fijos y variables de sus costos. El aumento en la flexibilidad tuvo como objeto la reducción de las ineficiencias que resultan de las no-convexidades en las estructuras de costos de los generadores térmicos. Estimamos y computamos un modelos estructural que cuantifica los efectos de este cambio en la eficiencia del despacho de energía y en los precios mayoristas. De forma consistente con resultados descriptivos previos, encontramos que bajo el nuevo mecanismo de despacho se incrementó la eficiencia, pero los precios se incrementaron. |
| Keywords: | Auctions, structural estimation, electricity markets, subastas, estimación estructural, mercados de electricidad |
| JEL: | C57 Q4 L94 |
| Date: | 2022–10 |
| URL: | http://d.repec.org/n?u=RePEc:bdr:borrec:1211&r= |
| By: | Timilsina,Govinda R.; Deluque Curiel,Ilka Fabiana; Chattopadhyay,Debabrata |
| Abstract: | Regional or cross-border trade of electricity would be beneficial for all trading partners for multiple reasons. However, cross-border electricity trade in Latin America is limited, and the potential benefits have been forfeited. This study estimates the potential savings on electricity supply costs if 20 Latin American countries allowed unrestricted trade of electricity between the borders without expanding their current electricity generation capacity. Two hypothetical electricity trade scenarios—unconstrained trade of electricity between the countries within the Andean, Central, and Mercosur subregions and full regional trade involving all 20 countries are simulated using a power system model. The study shows that the volume of cross-border electricity trade would increase by 13 and 29 percent under the subregional and regional scenarios, respectively. The region would gain US$1.5 billion annually under the subregional scenario and almost US$2 billion under the full regional scenario. More than half of this gain would be realized by the Andean subregion under both scenarios. These are short-term benefits without expanding the current electricity generation capacities. In the future, when countries add more generation capacity to meet their increasing demand, the potential benefits of electricity trade would be higher. A further study is needed to measure the increased benefits in the long run. |
| Keywords: | International Trade and Trade Rules,Energy Policies&Economics,Energy and Environment,Energy Demand,Energy and Mining,Oil Refining&Gas Industry,Power&Energy Conversion |
| Date: | 2021–06–08 |
| URL: | http://d.repec.org/n?u=RePEc:wbk:wbrwps:9692&r= |
| By: | Alberini,Anna; Umapathi,Nithin |
| Abstract: | In April 2015, the Government of Ukraine abruptly raised the tariffs of natural gas to residential customers, which were previously well below the cost of acquiring gas and delivering it to households. The tariff increase—700 percent—caused considerable distress to the population and led the government to scale up its existing energy assistance program, the housing and utilities subsidy program. This paper examines the welfare effect of the program and potential redesigns of the program. Using several waves of Ukraine’s Household Budget Survey, the analysis finds that electricity, gas, and fuels account for a considerable share of household income. After the tariff hike, the average household that did not receive the housing and utilities subsidy spends 11 percent of its income on electricity, gas, and fuels, implying that it meets the definition of “fuel poor.” The average share for households that do receive the subsidy is 6–8 percent. The housing and utilities subsidy cuts the rate of fuel poverty in half. It also brings considerable consumer surplus gains of 6–7 percent of income. This comes at a high price tag for the government, as the budget for the housing and utilities subsidy is 1–2.5 percent of gross domestic product. Considerable savings would be achieved with only a small loss of consumer surplus if the housing and utilities subsidy was cut in half. Linking the subsidy solely to income would also attain considerable savings, but at a high loss of welfare. The housing and utilities subsidy could also be paired with social tariffs, or an energy efficiency subsidy, with major savings for the government. |
| Keywords: | Oil Refining&Gas Industry,Energy Demand,Energy and Mining,Energy and Environment,Inequality,Energy Policies&Economics,Municipal Management and Reform,Urban Governance and Management,Urban Housing,Urban Housing and Land Settlements |
| Date: | 2021–05–21 |
| URL: | http://d.repec.org/n?u=RePEc:wbk:wbrwps:9669&r= |
| By: | E. Ruben van Beesten; Daan Hulshof |
| Abstract: | We consider a zonal international power market and investigate potential economic incentives for short-term reductions of transmission capacities on existing interconnectors by the responsible transmission system operators (TSOs). We show that if a TSO aims to maximize domestic total welfare, it often has an incentive to reduce the capacity on the interconnectors to neighboring countries. In contrast with the (limited) literature on this subject, which focuses on incentives through the avoidance of future balancing costs, we show that incentives can exist even if one ignores balancing and focuses solely on welfare gains in the day-ahead market itself. Our analysis consists of two parts. In the first part, we develop an analytical framework that explains why these incentives exist. In particular, we distinguish two mechanisms: one based on price differences with neighboring countries and one based on the domestic electricity price. In the second part, we perform numerical experiments using a model of the Northern-European power system, focusing on the Danish TSO. In 97% of the historical hours tested, we indeed observe economic incentives for capacity reductions, leading to significant welfare gains for Denmark and welfare losses for the system as a whole. We show that the potential for welfare gains greatly depends on the ability of the TSO to adapt interconnector capacities to short-term market conditions. Finally, we explore the extent to which the recently introduced European "70%-rule" can mitigate the incentives for capacity reductions and their welfare effects. |
| Date: | 2022–10 |
| URL: | http://d.repec.org/n?u=RePEc:arx:papers:2210.07129&r= |
| By: | Yihsu Chen; Andrew L. Liu; Makoto Tanaka; Ryuta Takashima |
| Abstract: | Distributed renewable resources owned by prosumers can be an effective way of fortifying grid resilience and enhancing sustainability. However, prosumers serve their own interests and their objectives are unlikely to align with that of society. This paper develops a bilevel model to study the optimal design of retail electricity tariffs considering the balance between economic efficiency and energy equity. The retail tariff entails a fixed charge and a volumetric charge tied to electricity usage to recover utilities' fixed costs. We analyze solution properties of the bilevel problem and prove an optimal rate design, which is to use fixed charges to recover fixed costs and to balance energy equity among different income groups. This suggests that programs similar to CARE (California Alternative Rate of Energy), which offer lower retail rates to low-income households, are unlikely to be efficient, even if they are politically appealing. |
| Date: | 2022–09 |
| URL: | http://d.repec.org/n?u=RePEc:arx:papers:2209.14505&r= |
| By: | OECD |
| Abstract: | Spectrum is a limited national resource that enables our digital world. Mobile broadband services rely on these invisible airwaves to function, making spectrum indispensable to bridge connectivity divides. It also supports the provision of wireless services across the economy, from education to healthcare to industry, and enables applications such as satellites, GPS and the Internet of Things. Spectrum must be efficiently managed to achieve broader social and economic goals. As such, the stakes of spectrum management decisions are high and the challenges complex. This report discusses the effective stewardship of this essential asset in the context of wireless communication services, presents trends in policy, and discusses future considerations for management. It finds that well-designed and transparent licensing regimes, including auctions, foster investment and innovation, and that flexible frameworks (e.g. sharing or unlicensed spectrum) can promote efficient use. |
| Date: | 2022–10–20 |
| URL: | http://d.repec.org/n?u=RePEc:oec:stiaab:332-en&r= |
| By: | Serzo, Aiken Larisa O. |
| Abstract: | This study reviews Philippine regulations governing digital platforms with cross-border operations and the impacts of these laws on the ability of platforms to innovate and participate in the global economy. There is no shortage of constitutional, statutory, and policy support for innovation, e-commerce, digitization, and entrepreneurship. However, there is a disconnect between these policies and the environment created by how implementing statutes and regulations evolved. These regulatory gaps could negatively impact digital platforms in two ways. First, they inhibit innovation because uncertainties could limit funding opportunities and discourage firms from developing or launching novel products. Second, gaps and overlaps could lead to cross-border and domestic regulatory arbitrage, forcing firms to relocate to areas or jurisdictions where risks are more manageable. Therefore, this paper recommends a recalibration of regulations, taking into consideration the policy objectives on innovation vis-Ã -vis the protection of Filipino consumers and entrepreneurs. Policymakers could take advantage of regulatory intersections to further innovation policies. They could also consider various interventions to achieve such reforms without necessarily resorting to constitutional changes. The government could review its taxation, labor, consumer protection, and investment regulations, ensuring that these laws do not stifle innovation. |
| Keywords: | regulatory reform; foreign direct investment;digital platforms; internet law; startups; internet economy; data privacy; mas media |
| Date: | 2021 |
| URL: | http://d.repec.org/n?u=RePEc:phd:rpseri:rps_2021-08&r= |
| By: | Saglam, Ismail |
| Abstract: | This paper studies the incentives for, and the welfare effects of, pre-donation in a vertically related industry where two downstream firms that produce a homogenous good jointly bargain, using the generalized Nash rule, with an upstream firm over a linear input price before they engage in Cournot competition. We theoretically show that the downstream industry has no incentive to make any pre-donation and this is irrespective of its bargaining power. We also show computationally that (i) the upstream firm finds to make unilateral pre-donation optimal if and only if its bargaining power is sufficiently small and (ii) its optimal pre-donation (whenever positive) always yields Pareto welfare gains. |
| Keywords: | Vertically related industry; Nash bargaining; pre-donation. |
| JEL: | C78 L12 L13 L22 |
| Date: | 2022–09 |
| URL: | http://d.repec.org/n?u=RePEc:pra:mprapa:114835&r= |
| By: | OECD |
| Abstract: | The communication sector is undergoing high-paced developments driven by the digital transformation of our economies and societies. Technological convergence has led to an evolving competitive landscape and new challenges arise around privacy and security concerns. Communication regulators are increasingly acknowledging the positive and negative effects of communication infrastructures and services on the environment. Moreover, there is a growing need to ensure the resilience of networks, stemming partially from the effects of climate change. In consequence, the key question for OECD policymakers is no longer whether regulatory structures need to change, but rather how. This report explores the critical role communication regulators play in an increasingly connected society. It identifies the challenges stemming from the digital transformation of our societies, the main policy objectives pursued by communication regulators, measures to address current and future challenges, as well as the importance of strengthening the capabilities of communication regulators of the future. |
| Date: | 2022–10–24 |
| URL: | http://d.repec.org/n?u=RePEc:oec:stiaab:333-en&r= |
| By: | Herrera Dappe,Matias; Melecky,Martin; Turkgulu,Burak |
| Abstract: | Public-private partnerships (PPPs) in infrastructure provision have expanded around the worldsince the early 1990s. Well-structured PPPs can unleash efficiency gains, but PPPs create liabilities forgovernments, including contingent ones. This paper assesses the fiscal risks from contingent liabilities from earlytermination of PPPs in a sample of developing countries. It analyzes the drivers of early termination and identifiessystematic contractual, institutional, and macroeconomic factors that can help predict the probability that a PPPproject will be terminated early, using a flexible parametric hazard regression. Using the probabilitydistributions from the regression analysis, it simulates scenarios of fiscal risks for governments from earlytermination of PPPs in the electricity and transport sectors, adopting a value-at-risk approach. The findingsindicate that the rate of early terminations decreases with direct government support, greater constraints on executivepower, and the award of the PPP by subnational governments; it increases with project size and macro-financial shocks.The simulations show that fiscal risks from infrastructure PPP portfolios are not negligible in some countries,reaching as high as 2.8 percent of GDP. A severe macro-financial shock substantially increases the estimates,with the value at risk the year after the shock 11–20 times larger. |
| Date: | 2022–03–15 |
| URL: | http://d.repec.org/n?u=RePEc:wbk:wbrwps:9972&r= |
| By: | Billette de Villemeur, Etienne; Cea-Echenique, Sebastián; Cuevas, Conrado |
| Abstract: | We revisit the consequences of uncertainty in the private provision of a public good. We show that, despite the risk aversion of agents and the decreasing returns to scale in the production function of the public good, uncertainty may improve welfare. This may hold true even if uncertainty leads to a reduction in the aggregate amount of donations for the production of the public good. This may also hold true when uncertainty makes the production of the public good more costly on average. Our findings suggest that regulation and control over the production process for public goods might not always be a desirable policy. |
| Keywords: | Public goods; Uncertainty; Control |
| JEL: | D64 D8 H41 |
| Date: | 2022–10 |
| URL: | http://d.repec.org/n?u=RePEc:pra:mprapa:114888&r= |
| By: | Quentin Gallea; Massimo Morelli; Dominic Rohner |
| Abstract: | This paper provides the first comprehensive empirical analysis of the role of natural gas for the domestic and international distribution of power. The crucial role of pipelines for the trade of natural gas determines a set of network effects that are absent for other natural resources such as oil and minerals. Gas rents are not limited to producers but also accrue to key players occupying central nodes in the gas network. Drawing on our new gas pipeline data, this paper shows that gas betweenness-centrality of a country increases substantially the ruler's grip on power as measured by leader turnover. A main mechanism at work is the reluctance of connected gas trade partners to impose sanctions, meaning that bad behavior of gas-central leaders is tolerated for longer before being sanctioned. Overall, this reinforces the notion that fossil fuels are not just poison for the environment but also for political pluralism and healthy regime turnover. |
| Date: | 2022–10 |
| URL: | http://d.repec.org/n?u=RePEc:arx:papers:2210.03572&r= |
| By: | Thapa,Dikshya; Farid,Muhammad Noor; Prevost,Christophe |
| Abstract: | This paper contributes to a long-standing debate in development practice: Under whatconditions can externally established participatory groups engage in the collective management of services beyond thelife of a project Using 10 years of panel data on water point functionality from Indonesia’s rural water program,the Program for Community-Based Water Supply and Sanitation, the paper explores the determinants of subnational variationin infrastructure sustainability. It then investigates positive and negative deviance cases to answer why somecommunities have successfully engaged in system management despite being located in difficult conditions as perquantitative findings and vice versa. The findings show that differences in the implementation of communityparticipation, driven by local social relations between frontline service providers, that is, village authoritiesand water user groups, explain sustainable management. This initial condition of state-society relations influences howthe project is initiated, kicking off negative or positive reinforcing pathways, leading to community collective actionor exit. The paper concludes that the relationships between frontline government representatives and community actorsare an important and underexamined aspect of the ability of external projects to generate successful community-ledmanagement of public goods. |
| Keywords: | Hydrology,Small Private Water Supply Providers,Water Supply and Sanitation Economics,Town Water Supply and Sanitation,Water and Human Health,Water and Food Supply,Energy Policies & Economics,Regional Governance,Social Accountability,Local Government |
| Date: | 2021–10–07 |
| URL: | http://d.repec.org/n?u=RePEc:wbk:wbrwps:9798&r= |
| By: | Joseph,George; Ayling,Sophie Charlotte Emi; Miquel-Florensa,Pepita; Bejarano,Hernán D.; Cardona,Alejandra Quevedo |
| Abstract: | In the past two decades, insights from behavioral sciences, particularly behavioral economics, have been widely applied in the design of social programs such as pensions, social security, and taxation. This paper provides a survey of the existing literature in economics on the application of behavioral insights to infrastructure sectors, focusing on water and energy. Various applications of behavioral insights in the literature are examined from the perspectives of the three main actors in the infrastructure sectors: policy makers, service providers, and consumers. Evidence is presented from the literature on how behavioral regularities, such as imperfect optimization, limited self-control, and nonstandard preferences, affect the strategies, decisions, and actions of policy makers, service providers, and consumers, often leading to suboptimal outcomes for service investment, delivery, access, and use. The paper also highlights how behavioral interventions such as anchoring, framing, nonpecuniary incentives, and altering the choice architecture can lead to improvements in performance, adoption, consumption, and other outcomes of interest in the infrastructure sectors. |
| Keywords: | Hydrology,Sanitary Environmental Engineering,Water Supply and Sanitation Economics,Town Water Supply and Sanitation,Small Private Water Supply Providers,Engineering,Sanitation and Sewerage,Water and Human Health,Health and Sanitation,Environmental Engineering,Energy and Mining,Energy and Environment,Energy Demand,Private Sector Economics |
| Date: | 2021–06–21 |
| URL: | http://d.repec.org/n?u=RePEc:wbk:wbrwps:9704&r= |
| By: | Hovhannisyan,Shoghik; Stamm,Kersten Kevin |
| Abstract: | Many developing countries face severe electricity constraints, which are reflected in lowelectrification rates, frequent and prolonged outages, and high electricity tariffs, all of which result in lowelectricity consumption that impedes economic development. This study estimates the impact of electricity consumptionon value added through reduced form equations for three sectors: agriculture, manufacturing, and services. It usespanel data on 126 countries for 1996–2014 from the International Energy Agency and World Development Indicatorsdatabases. To control for endogeneity and reverse causality bias in the ordinary least squares estimators, the studyapplies two-step difference and system panel generalized method of moments estimation techniques, which improve theordinary least squares estimates by applying lags of the explanatory variables as instruments that are not correlatedwith the error term and account for countries’ fixed effects generating bias in the coefficients. The estimation resultsindicate that electricity consumption has a significant and positive impact on the manufacturing sector’s value added innon-high-income countries (with an elasticity of 0.022). By contrast, the electricity consumption elasticities areinsignificant in agriculture and services in non-high-income countries, as the production technologies of theseindustries vary substantially across income groups compared with those in manufacturing. Finally, using all thecountries in the sample produce positive and significant results for all sectors, with the highest elasticity of0.036 in manufacturing. |
| Keywords: | Energy Policies & Economics,Food Security,Plastics & Rubber Industry,Pulp & Paper Industry,Textiles, Apparel & Leather Industry,General Manufacturing,Food & Beverage Industry,Common Carriers Industry,Construction Industry,Business Cycles and Stabilization Policies,Energy and Mining,Energy Demand,Energy and Environment,Economic Theory & Research,Industrial Economics,Economic Growth |
| Date: | 2021–10–21 |
| URL: | http://d.repec.org/n?u=RePEc:wbk:wbrwps:9815&r= |
| By: | Calderon,Cesar; Cantu,Catalina |
| Abstract: | This paper estimates the impact of digital infrastructure on economic growth and its sources.The analysis uses system generalized method of moments and finds evidence of a causal impact from the digitalinfrastructure variables to economic growth, its sources, income inequality, and poverty. The findings show thatmobile connections have an impact on economic growth through the total factor productivity growth channel, while internetusers drive it by the capital accumulation channel. Connections have a negative effect on the Gini coefficient,and internet users have a negative effect on the poverty headcount. The analysis also finds that human capital andaccess to electricity are important complementarities for digital infrastructure to reap benefits. There would belarge economic gains if Africa were to close the digital infrastructure gap relative to other regions, yet there aresome issues of affordability and skills that need to be addressed to reduce the usage gap and the digital divideacross gender, rural-urban, and firm size. |
| Keywords: | Economic Growth,Industrial Economics,Economic Theory & Research,Inequality,Information Technology,Telecommunications Infrastructure |
| Date: | 2021–11–18 |
| URL: | http://d.repec.org/n?u=RePEc:wbk:wbrwps:9853&r= |
| By: | Sabrina T. Howell; Yeejin Jang; Hyeik Kim; Michael S. Weisbach |
| Abstract: | Infrastructure assets have undergone substantial privatization in recent decades. How do different types of owners target and manage these assets? And does the contract form—control rights (concession) vs. outright ownership (sale)—matter? We explore these questions in the context of global airports, which like other infrastructure assets have been privatized by private firms and private equity (PE) funds. Our central finding is that PE acquisitions bring marked improvements in airport performance along a rich array of dimensions such as passengers per flight, total passengers, number of routes, number of airlines, cancellations, and awards. Net income increases after PE acquisitions, which does not reflect lower costs or layoffs. In contrast, in the few cases where non-PE acquisitions bring some improvement, it appears to reflect targeting rather than operational changes. Overall, we find little evidence that privatization alone increases airport performance; instead, infrastructure funds improve performance both in privatization and subsequent acquisitions from non-PE private firms. These effects are largest when there is a competing airport nearby. Finally, we show that outright ownership rather than control rights alone is associated with the most improvement after privatization. |
| JEL: | G32 G38 H54 L32 R42 |
| Date: | 2022–10 |
| URL: | http://d.repec.org/n?u=RePEc:nbr:nberwo:30544&r= |
| By: | Foster,Vivien; Rana,Anshul; Gorgulu,Nisan |
| Abstract: | Evidence of public expenditure on infrastructure is extremely sparse. Little is known aboutthe trends and patterns of infrastructure expenditure, and there is no real basis for assessing the adequacy andefficiency of infrastructure spending. Drawing on the World Bank’s novel BOOST database, this paper provides a firstrelatively disaggregated picture of infrastructure spending trends and patterns for a large sample of more than 70developing countries covering 2010–18, drilling down into expenditure by sector for roads as well as electricity, anddistinguishing operating from capital expenditure. Complementary sources of data are tapped to allow comparisonbetween expenditure patterns on and off budget. The study finds that on-budget expenditure on infrastructure has beenlow both in absolute terms (1 percent of gross domestic product) and relative terms (5 percent of total publicspending), as well as declining over time. Overall, infrastructure spending declined by about one-third over2010–18 (with the road sector bearing the brunt of the decrease), and now lies well below estimates of the requiredlevels, except in a handful of cases. There is evidence that low-income countries, despite lower spending envelopes,attach greater priority to public investment and infrastructure spending than their middle-incomecounterparts. Econometric analysis suggests that infrastructure spending in low- and middle-income countrieshas been historically procyclical, although to a lesser degree than total expenditure. In the transport sector, roadfunds are shown to play a substantial role in funding road maintenance, appearing to improve the adequacy of funding,while attenuating pronounced capital biases in road sector spending, but there is little evidence of efficiencyimprovements over time. |
| Keywords: | Transport Economics Policy & Planning,Roads & Highways,Financial Sector Policy,Energy Policies & Economics,Transport Services |
| Date: | 2022–01–14 |
| URL: | http://d.repec.org/n?u=RePEc:wbk:wbrwps:9903&r= |
| By: | Sautchuk-Patrício, Nathalia |
| Abstract: | In the various arenas of the Internet Governance debate, one of the points frequently highlighted is the need the need to maintain an 'open Internet'. Despite the common use of the term, which can be understood as a synonym for net neutrality, its meaning varies amongst the diverse cast of stakeholders. Internet governance can be seen as a polycentric mode of governance since the discussion takes place in different arenas and at varying levels. Moreover, these operate not exclusively in separate, individual ways but are connected through regulatory networks. Generally, polycentric governance contains three distinct structural layers to order dynamics: norms, practices and underlying orders. Also, this mode of governance manifests seven main attributes: trans-scalarity, trans-sectorality, diffusion, fluidity, over-lapping mandates, ambiguous hierarchies and the absence of a final arbiter. This text will revisit the net neutrality debate through a polycentric perspective, not used before to analyse this topic, as an approach to highlight some aspects of this discussion that were neglected in previous research. |
| Keywords: | Internet governance,polycentric governance,net neutrality |
| Date: | 2022 |
| URL: | http://d.repec.org/n?u=RePEc:zbw:khkgcr:31&r= |