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A Cournot model based on bounded inverse demand function and constant marginal production costs is studied. The case of three producers is considered and the adjustment process reduces to a three-dimensional noninvertible map in the output of competitors. The analysis of the dynamical behavior of the map is performed by the "critical curve method", extended to the critical surfaces in 3D. By this method, we explain the different bifurcations in the basins of attraction and in the attracting sets. In particular, given the economic application, feasible trajectories are focused, starting from the simple situation of two identical producers and extending the results to the generic case.

In this paper, we consider a two-dimensional map (a duopoly game) in which the fixed point is destabilized via a subcritical Neimark–Hopf (N–H) bifurcation. Our aim is to investigate, via numerical examples, some global bifurcations associated with the appearance of repelling closed invariant curves involved in the Neimark–Hopf bifurcations. We shall see that the mechanism is not unique, and that it may be related to homoclinic connections of a saddle cycle, that is to a closed invariant curve formed by the merging of a branch of the stable set of the saddle with a branch of the unstable set of the same saddle. This will be shown by analyzing the bifurcations arising inside a periodicity tongue, i.e., a region of the parameter space in which an attracting cycle exists.

This paper reconsiders the Cournot oligopoly (noncooperative) game with iso-elastic demand and constant marginal costs, one of the rare cases where the reaction functions can be derived in closed form. It focuses the case of three competitors, and so also extends the critical line method for non-invertible maps to the study of critical surfaces in 3D. By this method the various bifurcations of the attractors and their basins are studied. As a special case the restriction of the map to an invariant plane when two of the three firms are identical is focused.

This report examines adaptation and mitigation within an integrated framework. Global and regional costs of adaptation are assessed dynamically and the resulting benefits are quantified. This is accomplished by developing a framework to incorporate adaptation as a policy variable within three Integrated Assessment Models (IAMs); the global Dynamic Integrated model of Climate and the Economy (DICE), the Regional Integrated model of Climate and the Economy (RICE), and the World Induced Technical Change Hybrid (WITCH) model. The framework developed here takes into account investments in reactive adaptation and in adaptation "stocks", as well as investments in building adaptive capacity. This report presents the first inter-model comparison of results on adaptation costs using the emerging category of adaptation-IAMs. Results show that least-cost policy response to climate change will need to involve subsantial amounts of mitigation efforts, investments in adaptation stock, reactive adaptation measures and adaptive capacity to limit the remaining damages.

In this paper, we examine whether a minimum level of ensured consumption from a social safety net has the potential of breaking the vicious circle of risk avoidance and low return in African agriculture. We study how the implementation of a social safety net programme in Ethiopia has affected the value, risk and composition of farmers’ crop portfolios. The effects of programme participation on the value and risk of the crop portfolio are examined in a Just-Pope production function, and the effects of programme participation on composition of the crop portfolio are tested in a set of acreage response models. The empirical analysis is based on unique household panel data that allow us to control for unobserved heterogeneity. No significant effect on the value and risk of the crop portfolio could be found. However, the programme seems to have brought about some changes in the land allocated to different crops. The greatest effect is towards increased cultivation of perennials, which are high-value, high-risk crops in this part of Ethiopia.

This thesis consists of a summary and four self-contained papers.

Paper [I] examines whether the implementation of a social safety net programme in Ethiopia has affected the value, risk and composition of farmers‟ crop portfolios. The empirical analysis suggests that the value and risk of the crop portfolio have not been altered due to the programme. However, the programme seems to have brought about some changes in the land allocated to different crops.

Paper [II] studies how a social safety net affects farmers‟ (dis)investments in productive assets. More specifically, it studies how the Productive Safety Net Programme in Ethiopia has changed livestock and tree holdings. The results indicate no significant effect on livestock holdings, but a significant increase in tree holdings.

Paper [III] investigates if there is a problem of adverse selection in formal microlending in rural Bangladesh. The results indicate that farmers who only borrow formally have a shadow price of capital that is substantially higher than the average informal interest rate. This suggests that farmers that only borrow formally are perceived as poor credit risks by informal lenders.

Paper [IV] explores the economic incentives surrounding the cultivation of opium poppy in Afghanistan. Specifically, it examines the impact of eradication policies when opium is used as a means of obtaining credit, and when the crops are produced in sharecropping arrangements. The results indicate that both these features are likely to affect the outcome of eradication policies.

In this paper, we model the economic incentives surrounding opium crop production at farm level in Afghanistan. Specifically, we examine the impact of eradication policies when opium is used as a means of obtaining credit, and when the crops are produced in sharecropping arrangements. The theoretical analysis suggests that when perfect credit markets are available, an increased risk of having the opium poppy eradicated will lead to less land being allocated to opium poppy. Thus, with perfect credit markets, the eradication policy is likely to have the intended effect of lowering opium crop production. However, when opium is sold on futures markets as a means of obtaining credit, the effects of opium eradication are no longer clear-cut: in some cases the outcome may actually increase the land allocated to opium poppy. Finally, the results indicate that when opium is produced in sharecropping arrangements, increased risk of opium eradication will unambiguously make the tenants worse off, while landlords may actually benefit.

We evaluated the impacts of the Ethiopian Productive Safety Net Program (PSNP) on rural households' holdings of livestock and forest assets/trees. We found no indication that participation in PSNP induces households to disinvest in livestock or trees. In fact, households that participated in the program increased the number of trees planted, but there was no increase in their livestock holdings. We found no strong evidence that the PSNP protects livestock in times of shock. Shocks appear to lead households to disinvest in livestock, but not in trees. Our results suggest that there is increased forestry activity as a result of PSNP, and that improved credit access encourages households to increase their livestock holdings.

Microcredit schemes have become a popular means of improving smallholders' access to credit and making long term investment possible. However, it remains to be explored whether the current microcredit schemes are more successful than earlier formal small scale lending in identifying successful borrowers. We studied shrimp farming in a rural region in Bangladesh where formal microlending is well established, but where more expensive informal microlending coexists with the formal schemes. Farmers - both those who exclusively use formal loans and those who also use informal loans - remain credit-constrained; both types overutilize labour in order to reduce the need for working capital. However, the credit constraint is actually milder for the informal borrowers: the implicit shadow price of working capital is substantially higher in the group that only takes formal loans than in the group that also uses informal loans. These results suggest that informal lenders - with their closer ties to the individual farmers - remain more successful in identifying those smallholder farmers that are most likely to use the borrowed funds successfully. Informal lenders have an information advantage that formal microlenders lack: the latter need to find routes to access this information in order for formal microcredit schemes to succeed.

It is well known that cigarette smoking and the use of other addictive goods is harmful to health. Still, some people smoke cigarettes and drink alcohol in their daily lives. The consumption of addictive goods seems, therefore, to be the antithesis of rational behavior. In this article, however, it is demonstrated that a rational individual, in the sense that he or she maximizes his or her well-being while anticipating the future consequences of his or her choices, may in fact choose to consume addictive goods. Specifically, the two-good extension of the rational addiction model is demonstrated and related to relevant policy questions. For instance, should one encourage the use of smokeless tobacco in smoking cessation programs? According to the empirical results, the answer is no. Further, should one discourage smoking by increasing the tax on cigarettes? Again, the answer is no.

The purpose of this paper is to investigate regional effects of military base closures in Sweden during the last decades. Our analysis is based on a regional growth model, where two equations are estimated; one equation describing the average income growth rate and one equation describing the net migration rate. The data set is a panel of 31 Swedish municipalities covering the period 1983-1998. Our main finding is that a closure of a military base has not had any significant impact on the subsequent average income growth rate nor the net migration rate in the affected municipalities. One potential explanation for these results relates to the labour market and the composition of the labour force.

This paper concerns the effects of military closures on the local growth pattern in Sweden during the last decades. The main issue is to analyze to what extent the closures have affected the subsequent average income growth and net migration rates at the local level. The analysis is based on a data set covering Swedish municipalities with military bases during the period 1983-1998. Our main finding is that the closures have not had any significant impact on the subsequent income growth rate or the net migration rate in the affected minicipalities compared to other municipilaties. However, in accordance with previous studies based on Swedish data, we find the initial endowment of human capital to have a positive impact on the subsequent growth rate.

The thesis comprises five papers and an introductory overview of applied models and methods. The papers concern interdependences and interrelations in models applied to empirical analyses of various problems related to production, consumption, location and trade. Among different definitions of 'structural analysis' one refers to the study of the properties of economic models on the assumption of invariant structural relations, this definition is close to what is aimed at in lire present case.

Although the subjects cover widely differing aspects of the economic system, applied models and methods, i.e. entropy maximizing (information minimizing) models and random utility maximizing models, are in many cases closely connected.

Tlic first paper reports on a regional input-ouput study applied to Norrbotten, Sweden. The paper is mainly concentrated on developing and estimating an econometric model, describing the structural interdependences in the Norrbotten economy. The chapter is composed of three parts. The first part concerns the theoretical basis of the model, the main fields of application and principal problems in connection with the estimation. The core of the estimated model is defined by the intersectoral dependences in the Norrbotten economy. This model can be viewed as a part of a more general model of the regional economy, and such a general model is briefly outlined.

The second part reports on the collection and arranging of data, and the methods used for the estimation of the model. In the third part the results are presented. A special interest concerns the effects of production changes in the basic industries in the county, as to the expected impact on different industries and occupational groups.

The second paper concerns some aspects of the problem of predicting trade flows in the forest sector. The model, based on information theory, is predicting current trade flows by adjusting the historical, a priori, trade flows to satisfy current export and import totals.

In the third paper an entropy model is employed to decompose the interregional and intraregional employment change in Sweden and Stockholm, during the period 1960 - 1980, into effects attributed to regions (zones), industries, occupations and interaction effects.

The fourth paper presents an empirical analysis of housing choice, based on individual data of households in Stockholm. The consumer choice is regarded as a complex choice from a finite set of discrete alternatives and a probabilistic choice mode! (multinomial logit) is employed, where secondary dwelling is included in the housing choice decision.

In the final paper spectral analysis is used for identifying the significant components of cycle behaviour in time series of Swedish exports of forest products over a twenty year time period.

This paper uses a labor supply model that incorporates waiting for health care to derive an empirical specification for sick leave and to estimate the impact of waiting for health care on the duration of sick leave. In the estimations, we use the 2002 sample of the RFV-LS register database, supplemented with information from questionnaires. The results indicate that almost all waiting for health care variables have a statistically significant positive impact on the duration of sick leave, and did not induce substantial changes on the impact of traditional variables of the labor supply model.

In this paper, we calculate time series of shadow prices for Swedish emissions of CO2, SO2, and VOC for the period 1918 - 1994. Newly constructed historical emission time series enable studying a single country’s emission paths through increasing levels of economic activity. The shadow prices are, in the next step, related to income to explain the environmental Kuznets curves (EKC) previously found in Swedish data for these three emissions. A directional distance function approach is used to estimate the production process for Swedish industry thus enabling the opportunity costs of a reduction in these emissions to be calculated. We attribute the annual changes in the shadow prices to the main causal factors by decomposing them into a technological effect and a substitution effect. We conclude that the time series of the shadow prices show support for EKCs for Swedish industry.

This thesis consists of four papers: two of them deal with the effects on the forest sector of an increase in the demand for forest fuels, and two of them concern the relation between economic growth and pollution.

Paper [I] is a first, preliminary study of the potential effects on the Swedish forest sector of a continuing rise in the use of forest resources as a fuel in energy generation. Sweden has made a commitment that the energy system should be sustainable, i.e., it should be based on renewable resources. However, an increasing use of the forest resources as an energy input could have effects outside the energy sector. We consider this in a static model by estimating a system of demand and supply equations for the four main actors on the Swedish roundwood market; forestry, sawmills, pulpmills and the energy sector. We then calculate the industries' short run supply and demand elasticities.

Paper [II], is a development of the former paper. In this paper, we estimate the dynamic effects on the forest sector of an increased demand for forest fuels. This is done by developing a partial adjustment model of the forest sector that enables short, intermediate, and long run price elasticities to be estimated. It is relevant to study the effects of increased demand for forest fuels as the Swedish government has committed to an energy policy that is likely to further increase the use of renewable resources in the Swedish energy system. Four subsectors are included in the model: forestry, sawmills, pulpmills and the energy industry. The results show that the short run elasticities are fairly consistent with earlier studies and that sluggish adjustment in the capital stock is important in determining the intermediate and long run responses. Simulation shows that an increase in the demand for forest fuels has a positive effect on the equilibrium price of all three types of wood, and a negative effect on the equilibrium quantities of sawtimber and pulpwood.

In paper [III] a Shephard distance function approach is used to estimate time series of shadow prices for Swedish emissions of CO2, SO2, and VOC for the period 1918 - 1994. The shadow prices are in a next step regressed on GDP per capita. The objective of the study is closely linked to hypothesis of environmental Kuznets curves. We conclude that the time series of the shadow prices from this approach can not be used to explain the EKCs found for Swedish emissions.

In paper [IV], we calculate time series of shadow prices for Swedish emissions of CO2, SO2, and VOC for the period 1918 - 1994. The shadow prices are in a next step related to income, to explain the EKCs previously found for Swedish data on the three emissions. Newly constructed historical emission time series enable studying a single country's emission paths through increasing levels of economic activity. A directional distance function approach is used to estimate the industry's production process in order to calculate the opportunity costs of a reduction in the emissions. The time series of the shadow prices show support for EKCs for the Swedish industry.

In this paper, we estimate the dynamic effects on the forest sector of an increased demand for biofuels. This is done by developing a partial adjustment model of the forest sector that enables short, intermediate, and long run price elasticities to be estimated. It is relevant to study the effects of increased demand for biofuels as the Swedish government has committed to an energy policy that is likely to further increase the use of renewable resources in the Swedish energy system. Four subsectors are included in the model: the forest owners, who supply sawtimber, pulpwood and forest fuels; the sawmills which demand sawtimber; the pulp and paper industry which demands pulpwood; and the energy industry which demands forest fuels. The results show that the short run elasticities are fairly consistent with earlier studies and that sluggish adjustment in the capital stock is important in determining the short and intermediate run responses. Simulation shows that an increase in the demand for forest fuels has a positive effect on the equilibrium price of all the three types of wood, and a negative effect on the equilibrium quantities of sawtimber and pulpwood.

In this note, we estimate time series of shadow prices for Swedish emissions of CO2, SO2 , and VOC for the period 1918 - 1994. The shadow prices are in the second step related to income to explain the environmental Kuznets curves previously found for Swedish data on the three emissions. A Shephard distance function approach is used to estimate a structural model of the industry’s production process in order to calculate the opportunity costs of a reduction in the emissions. We conclude that the times series of the shadow prices obtained using this approach do not show support for EKCs for Swedish industry.

This paper concerns redistribution and public good provision under asymmetric information, which are here ingredients of a policy-problem facing each member state (nation) of an economic federation with decentralized leadership. Each member state is assumed to have its own redistributive policy and pattern of public consumption, whereas the federal level redistributes (ex-post) between the member states. The results show how and why federal ex-post redistribution may modify the use of income taxation and public good provision at the national level, relative to the policy outcome in the absence of a federal government, as well as how the national policy incentives depend on whether or not the federal government uses distortionary taxes.

This article contributes to the theory of social accounting. As such, it tries to extend earlier literature on the welfare equivalence of the comprehensive net national product in two main directions, both of which refer to the public sector. One is by considering welfare measurement problems associated with public good provision and redistributive policy, respectively, when the public revenues are raised by distortionary taxes. The other is by addressing the consequences of a “federation-like” decision structure, where independent tax and expenditure decisions are made both by the central government and by lower level governments.

This paper concerns welfare measurement in an economy with union wage setting, where the equilibrium is characterized by unemployment. Contrary to results derived in the first best, the current value Hamiltonian is not an exact welfare measure in an economy with unemployment. Instead, the welfare measure also depends on “employment effect,” which are caused by the discrepancy between supply and demand in the labor market. In addition, since unemployment gives rise to heterogeneity, distributional effects will also characterize the welfare measure.

This paper analyses the potential welfare gains of introducing a technology transfer from Annex I to non-Annex I in order to mitigate greenhouse gas emissions. Our analysis is based on a numerical general equilibrium model for a world-economy comprising two regions; North (Annex I) and South (non-Annex I). In a cooperative equilibrium, a technology transfer from the North to the South is clearly desirable from the perspective of a ‘global social planner’, since the welfare gain for the South outweighs the welfare loss for the North. However, if the regions do not cooperate, then the incentives to introduce the technology transfer appear to be relatively weak from the perspective of the North; at least if we allow for Southern abatement in the pre-transfer Nash equilibrium. Finally, by adding the emission reductions associated with the Kyoto agreement, our results show that the technology transfer leads to higher welfare in both regions.

This paper addresses optimal taxation, when therelationship between the consumption of a`dirty' good and the resulting environmentaldamage is uncertain and treated as a randomvariable by policy makers. The main purpose isto analyze how increased uncertainty, measuredas a mean preserving increase in the spread ofthis random variable, affects the optimalcommodity tax on the dirty consumption good. Incase the only task of government is to correctthe environmental externality, and if thepreferences are characterized by nondecreasingabsolute risk aversion, we find that thecommodity tax on the dirty consumption goodincreases in response to additionaluncertainty. If, on the other hand, thegovernment provides a public good and uses alump-sum tax in addition to the commodity tax,it is possible that the commodity tax decreasesas a response to additional uncertainty, evenif the preferences are characterized bynondecreasing absolute risk aversion. A similarresult emerges, although for different reasons,if the lump-sum tax is replaced by a laborincome tax.

This paper concerns transboundary environmental problems in the context of an optimal tax model. We assume that part of the labor force is mobile across countries, and that the set of tax instruments includes a nonlinear income tax and a commodity tax on the ‘dirty’ good that is causing damage to the environment. The purpose is to compare the (globally optimal) second best policy of a cooperative equilibrium with the policy implicit in a noncooperative equilibrium. We show that the commodity taxes differ between equilibria because of: (i) transboundary externalities not internalized by national governments, (ii) interaction effects between environmental and other policies, and (iii) labor mobility.

This paper concerns redistribution and public good provision in an economic federation with two levels of government: a local government in each locality and a (first mover) central government. Each locality is characterized by two ability-types, and the ability-distribution differs across localities. The central government redistributes via a nonlinear income tax and a lump-sum transfer to each local government, while the local governments use proportional income taxes and provide local public goods. We show how the redistributive role of taxation is combined with a corrective role, and how the central government can implement the second best resource allocation.

We consider a model with a population consisting of earners and retired persons; elderlycare is publicly provided. There is one big city, where congestion effects and agglomerationforces are at work, and a number of small villages. We show how the externalities related topopulation mobility lead to an inefficient spatial distribution of earners and retirees, and wecharacterize the second-best solution. Decentralization of this solution in a fiscal federalismstructure requires the use of taxes and subsidies proportional to the number of earners andretired persons living in the city and the villages.

This paper deals with optimal income taxation based on a household model, where men and women allocate their time between market work and household production, and where households differ depending on which spouse has the comparative advantage in market work. The purpose is to analyze the tax policy implications of gender norms represented by a market work norm for men and household work norm for women. We show how the optimal (corrective) tax policy depends on the definition of social norms, the preferences for obeying these norms, and whether men or women have the comparative advantage in market work. Two extreme results are that (i) corrective taxation should not be used at all if the norms are based on the mean value of market work and household work, respectively, given that all households have the same preferences, and (ii) only the majority household type should be taxed at the margin if the norms are instead based on the modal value.

This paper analyzes the welfare effects of a publicly provided private good with long-term consequences for individual well-being, in an economy where consumers have present-biased preferences due to quasihyperbolic discounting. The analysis is based on a two-type model with asymmetric information between the government and the private sector, and each consumer fives for three periods. We present formal conditions under which public provision to the young and the middle-aged generation, respectively, leads to higher welfare. Our results show that quasihyperbolic discounting provides a strong incentive for public provision to the young generation - especially if the consumers are naive (as opposed to sophisticated).

This paper concerns the provision of a state-variable public good in a two-type model under present-biased consumer preferences. The preference for immediate gratification facing the high-ability type weakens the incentive to adjust public provision in response to the self-selection constraint.

This article concerns optimal income taxation under asymmetric information in a two-type OLG model when individuals' relative consumption matters. Positional concerns affect the policy choices via two channels: (i) the average degree of positionality and (ii) positionality differences between the low-ability type and the mimicker. Under plausible empirical estimates, the marginal labor income tax rates become substantially larger, and the absolute value of the marginal capital income tax rate of the low-ability type becomes substantially smaller, than in the conventional model. In addition to measures of reference consumption based on average consumption, we also address within-generation and upward comparisons.

This paper concerns the optimal provision of a state-variable public good, where the global climate is the prime example. The analysis is based on a two-type optimal income tax model with overlapping generations, where people care about their relative consumption. We consider both keeping-up-with-the-Joneses preferences (where people compare their own current consumption with others’ current consumption) and catching-up-with-the-Joneses preferences (where people compare their own current consumption with others’ past consumption). The extent to which the rule for public provision ought to be modified is shown to depend crucially on the preference elicitation format.

Almost all previous studies on public policy under relative consumption concerns have ignored the role of leisure for status comparisons. Inspired by Veblen (1899), this paper considers a two-type optimal income tax model, where people care about their relative consumption, and where the importance of relative consumption increases with the use of leisure due to increased consumption visibility. We show that increased consumption positionality typically implies higher marginal income tax rates for both ability-types. Using a leisure-weighted measure of reference consumption, rather than a measure where leisure plays no role as in the previous literature, increases the marginal income tax rate implemented for the low-ability type and decreases the marginal income tax rate implemented for the high-ability type, i.e., it gives rise to a regressive tax component.