This thesis discusses jurisdiction to tax cross-border digital commerce. The primary objective is to consider the reasons for the erosion of jurisdictional links, or nexus, between countries and taxpayers' digital activities and evaluate possible solutions for addressing such nexus erosion. Whilst it is argued that digital commerce is impossible to ring-fence due to digital technologies transcending all industries, the main focus of this research is on automated business models as case studies for the broader tax issues applicable across the entire digital economy. Using cloud computing, online advertising and e-tailing models as examples of digital commerce in the narrow sense, this thesis demonstrates that the proxies for establishing jurisdictional nexus have become increasingly fluid, thereby challenging the traditional international tax regimes for profits and consumption taxation. Numerous policy solutions have been proposed in order to rectify nexus erosion, including global and territorial tax models. Unlike the previous research in this area, this thesis focuses on the nexus elements of such proposals and assesses their viability in the light of the wider Internet governance jurisprudence. Global tax solutions, such as global e-commerce taxes and formulary apportionment, are analysed in the context of the international governance regime for the technical Internet infrastructure. Territorial virtual tax solutions, such as virtual permanent establishments, withholding taxes and destination cash flow taxes, are considered in the light of the Internet jurisprudence on the 'effects' and 'targeting' nexus standards. It is argued that, given the lack of technical and political infrastructure, none of the proposed routes would be viable from a practical perspective in the near future. It is concluded, therefore, that a practical solution would involve retaining the traditional profits and consumption tax models, whilst testing a narrow version of the digital targeting nexus standard as a backstop anti-abuse measure. It is envisaged that the limited anti-avoidance provision would subsequently pave the way for a comprehensive long-term solution, as digitisation continues to transform global commerce.

This thesis aims to provide new and useful insights into the effects that various tax, labour and product market reforms have on the overall economic performance. Additionally, it aims also to provide insights about the optimal monetary and fiscal policy behaviour within the economy characterized with various real labour market frictions. We analyze the benefits of tax reforms and their effectiveness relative to product or other labour market reforms. A general equilibrium model with imperfect competition, wage bargaining and different forms of tax distortions is applied in order to analyze these issues. We find that structural reforms imply short run costs but long run gains; that the long run gains outweigh the short run costs; and that the financing of such reforms will be the main stumbling block. We also find that the effectiveness of various reform instruments depends on the policy maker's ultimate objective. More precisely, tax reforms are more effective for welfare gains, but market liberalization is more valuable for generating employment. In order to advance our understanding of the tax and product market reform processes, we then develop a dynamic stochastic general equilibrium model which incorporates search-matching frictions, costly ring and endogenous job destruction decisions, as well as a distortionary progressive wage and a at payroll tax. We confirm the negative effects of marginal tax distortions on the overall economic performance. We also find a positive effect of an increase in the wage tax progressivity and product market liberalization on employment, output and consumption. Following a positive technology shock, the volatility of employment, output and consumption turns out to be lower in the reformed economy, whereas the impact effect on inflation is more pronounced. Following a positive government spending shock the volatility of employment, output and consumption is again lower in the reformed economy, but the inflation response is stronger over the whole adjustment path. We also find detrimental effects on employment and output of a tax reform which keeps the marginal tax wedge unchanged by partially offsetting a decrease in the payroll tax by an increase in the wage tax rate. If this reform is anticipated one period in advance the negative effects remain all over the transition path. We investigate the optimal monetary and fiscal policy implication of the New-Keynesian setup enriched with search-matching frictions. We show that the optimal policy features deviation from strict price stability, and that the Ramsey planner uses both inflation and taxes in order to fully exploit the benefits of the productivity increase following a positive productivity shock. We also find that the optimal tax rate and government liabilities inherit the time series properties of the underlying shocks. Moreover, we identify a certain degree of overshooting in inflation and tax rates following a positive productivity shock, and a certain degree of undershooting following a positive government spending shock as a consequence of the assumed commitment of policy maker.

La fiscalité locale vue comme l’ensemble des mécanismes juridiques régissant la collecte des impôts locaux au profit en totalité ou en partie des collectivités locales apparaît au Cameroun avec la création formelle des villes en 1944. Avant cette réorientation de la fiscalité dans le Territoire du Cameroun sous tutelle, elle est en réalité un outil de domination coloniale au service des intérêts de la Puissance mandatrice. Au lendemain de l’indépendance du pays en 1960, le système fiscal local demeure inchangé avec la prédominance des CAC et une kyrielle de taxes et redevances dont la productivité demeure faible. La timide reforme de 1974 qui a pour but réel d’uniformiser le système fiscal après la réunification des deux Cameroun (Anglophone et Francophone) n’apporte en définitive aucune innovation majeure. Les mêmes difficultés persistent et s’empirent même avec la crise économique des années 90. Au-delà des facteurs externes, ces difficultés sont liées d’une part à l’archaïsme du mode d’organisation administrative et d’autre part à la faiblesse de la législation. Un espoir naît avec la réforme de 2009, fruit du processus de décentralisation en cours au Cameroun. Cette réforme, malgré ses avancées, reste toutefois en deçà des attentes et les collectivités locales dans leur immense majorité croupissent toujours dans l’extrême pauvreté. De nouveaux processus de recherche de ressources fiscales et non fiscales sont de plus en plus expérimentés, faisant la part belle à des partenariats de tous types et aussi à l’extension plus grande de la matière imposable au niveau local. Ces avancées pour plus d’efficacité auront fortement besoin d’une nouvelle forme d’administration de l’impôt local et d’un renforcement du dispositif législatif et réglementaire en s’efforçant de créer de meilleures relations entre l’Administration et les contribuables et aussi, puiser des expériences réussies ailleurs dans d’autres pays Africains de même niveau de développement. La réforme est possible contrairement à une idée véhiculée par les afro-pessimistes. Pour cela, un diagnostic clair de la situation doit être fait et accepté par l’autorité centrale mais aussi par les autorités locales et ensuite toutes les solutions mises en exergue dans cette étude devraient suffire pour sortir la fiscalité locale au Cameroun de sa torpeur. / Local taxes as all of the legal mechanisms for the collection of local taxes for the benefit in whole or in part of local communities appear in Cameroon with the formal creation of the cities in 1944. Before this reorientation of the taxation in the territory of Cameroon under trusteeship, it is actually a tool of colonial domination in the service of the interests of the colonial power. In the aftermath of the country's independence in 1960, the local tax system remains unchanged with the predominance of the ACC and a myriad of taxes and fees including productivity remain low. The timid reform of 1974 which has the real purpose of standardize the tax system after the reunification of the two Cameroon (Anglophone and Francophone) does in the end no major innovation. The same difficulties persist and worsen even with the economic crisis of the 1990s. Beyond the external factors, these difficulties are related to the bigotry of the administrative organization mode and on the other hand the weakness of legislation. A hope was born with 2009 reform, fruit of the ongoing decentralization process in Cameroon. This reform, despite its advances, rest however only below expectations and local communities in their vast majority are still in extreme poverty. New resources tax and nontax research processes are more experienced, strong partnerships of all kinds and the greater extension also taxable matter at the local level. These advances for efficiency strongly need a new form of administration of local tax and a strengthening of the legislative and regulatory system in striving to create better relations between the Administration and the taxpayers and also draw successful experiences elsewhere in other African countries at the same level of development. Reform is possible contrary to mediated by the afro-pessimists. For this, a clear diagnosis of the situation must be made and accepted by the central authority, but by local authorities and then all the implemented solutions highlight in this study should be sufficient to leave local taxation in Cameroon from its torpor.

La TVA est une taxe ad valorem facturée par les entreprises à leurs clients mais dont seule la différence entre la taxe collectée par l’entreprise et celle qu’elle a supportée sur ses achats est reversée à l’ Etat. Selon ce mécanisme, la TVA repose uniquement sur la consommation finale et semble adaptée aux principes d’une taxe indirecte optimale pour la maximisation du bien-être collectif. Cependant, dans les PED, la taille de l’assiette, les problèmes de remboursement des crédits de TVA et le non assujettissement de certains producteurs, modifient le fonctionnement de la taxe. Afin d’appréhender l’impact de la TVA dans les PED avec un nouveau regard, les effets de la taxe sur l’allocation des ressources et la distribution des revenus sont étudiés à l’aide d’un Modèle d’ Equilibre Général Calculable ad hoc appliquée à des problématiques spécifiques au Niger et au Sénégal. Les résultats des simulations montrent que l’analyse de l’impact de la TVA ne peut pas se contenter d’un discours commun, ni du point de vue du consommateur, ni de celui du producteur. / In theory, VAT has always been considered as a consumption tax (Lauré, 1957). Liable producers transfer to the government the difference between the VAT collected on sales and the VAT paid on their inputs. VAT is therefore a tax on final consumption born by the consumer and collected by the producer. With tax abatement principle, VAT seems adapted to the principals of an optimal indirect tax for the maximization of the collective wellbeing. However, if VAT exemptions are implemented or if the tax administration is inefficient in issuing refunds for VAT credits or simply due to non-liable producers, VAT increases producer’s tax burden and viewing the VAT only as a consumption tax becomes inaccurate. In order to take into account these complexities, we built the first Computable General Equilibrium Model in order to shed some light on resources allocation and income distributions of the tax in Niger and Senegal. Simulation results show that an analysis of the VAT’s impact cannot rely only on a common line, neither from the consumer’s nor the producer’s point of view.

The main goal of this thesis is to provide a sociologically informed analysis of tax avoidance and tax evasion in contemporary Mexico and Sweden, focusing particular attention on the explanatory role of social networks, social interactions, and positive feedback mechanisms. Two major data sources are used: (1) A panel dataset that includes all persons, 16 years or older, who resided in Stockholm County during at least one of the years 1990 to 2003 (N=1,967,993). The dataset includes detailed information on the socio-demographic characteristics, kinship networks, and criminal offences of these individuals; (2) A random sample of 36,949 firms that appeared in the Mexican Federal Register of Taxpayers for the year 2002. The records of the Mexican Federal Administrative Fiscal Tribunal provided data on all types of tax claims appealed before them during the 2002-2008 period. A variety of approaches and techniques are used such as agent-based simulation models, discrete time event history models, random effect logit models, and hierarchical linear models. These models are used to test different hypotheses related to the role of social networks, social interactions, and positive feedback mechanisms in explaining tax behaviour. There are five major empirical findings. (1) Networks seem to matter for individuals' tax behaviour because exposure to tax crimes of family members appears to increase a person’s likelihood of committing a tax crime. (2) Positive feedback mechanisms appear relevant because if a person commits a tax crime, it seems to increase the likelihood that the person will commit more tax crimes in the future. (3) Positive feedback mechanisms are also important for explaining corporate tax behaviour because a firm that has engaged in legal tax avoidance in the past appears to be more likely to engage in tax avoidance in the future. (4) Network effects are important in the corporate world because exposure to the tax avoidance of other firms increase the propensity of a firm to engage in tax avoidance. (5) Substitution effects between tax evasion and tax avoidance are likely to exist because when tax evasion becomes more prevalent in a firm’s environment, their likelihood of engaging in legal tax avoidance is lowered. The results underscore the importance of a sociological perspective on tax behaviour that takes into account social interactions and positive feedback mechanisms. In order to understand microscopic as well as macroscopic tax evasion patterns, the results presented in this thesis suggest that much more attention must be given to mechanisms through which taxation crimes breed more taxation crimes.

Une réforme efficace et efficiente du secteur public constitue un enjeu important pour les gouvernements et les partenaires au développement partout dans le monde. La décentralisation budgétaire ̶ le transfert de compétences en matière de recettes et de dépenses du gouvernement central vers les gouvernements locaux ̶ est souvent considérée comme un moyen d’améliorer l’efficacité de la mobilisation des ressources domestiques et de renforcer l’accès et la qualité des services publics. Dans la poursuite de ces objectifs, la décentralisation budgétaire est devenue un élément essentiel de la politique de réforme du secteur public dans de nombreux pays surtout ceux en développement. Face à l’importance des enjeux liés à cette réforme notamment sur les finances publiques, une importante littérature économique s’est attachée à étudier ses conséquences et les conditions de sa réussite. Cette thèse contribue à cet effort à travers quatre chapitres portant sur les effets de la décentralisation budgétaire dans les pays en développement et plus précisément en Côte d’Ivoire.Le premier chapitre analyse les conséquences de la mobilisation fiscale au niveau municipal sur l’accès aux services publics et sur la réduction de la pauvreté. Les résultats suggèrent que l’augmentation des revenus des municipalités accroît l’accès aux services publics, notamment l’éducation, et, dans une moindre mesure, réduit la pauvreté. Cet effet est accentué dans les régions à faible diversité ethnolinguistique et en milieu urbain. Le second chapitre évalue les effets de l’autonomie fiscale des municipalités sur la distribution de revenus de la population. Empiriquement, les résultats suggèrent qu’une augmentation des revenus prélevés par le gouvernement central (et rétrocédés aux municipalités) réduit les inégalités de revenus, alors qu’une augmentation des revenus directement prélevés par les municipalités augmente les inégalités (taxes locales). Le chapitre trois (3) analyse dans quelle mesure les transferts du gouvernement central aux municipalités affectent la mobilisation des revenus de ces dernières. Les résultats montrent qu’une augmentation des transferts augmente les revenus des municipalités provenant des impôts rétrocédés, et, dans une moindre mesure, les taxes locales. Le quatrième chapitre porte sur les déterminants de la conformité des taxes foncières. Nos résultats concluent que la conformité des taxes foncières est déterminée, entre autres, par les niveaux de services publics du gouvernement central et des municipalités, de la confiance des citoyens envers les municipalités et de la compréhension des citoyens du système de taxation. Les résultats de cette thèse induisent d’importantes implications en termes de politiques de renforcement du secteur public. / An effective and efficient public-sector reform enhances government capability to raise domestic revenue for prioritized spending. It also contributes to strengthening the government capacity to manage public resources more effectively and deliver public services. In pursuing these objectives, fiscal decentralization, the devolution of taxing and spending powers to lower levels of government, has become a key public-sector reform in many countries. Given such high stakes, a growing economic literature is focusing on how to better understand the challenges developing countries face in implementing fiscal decentralization reforms. The present thesis adds to this effort through four contributions shedding light on specific issues related to fiscal decentralization.Chapter 1 analyses whether and how municipal revenue mobilization could enhance citizens’ access to public services and reduce poverty. The results indicate that increasing municipal-raised revenues improve access to public services and reduce poverty. This effect works mainly through enhancing access to education than on access to health, especially in less ethnically diverse localities and in urban zones. Chapter 2 investigates the effect of municipal revenue autonomy on inequalities within sub-national governments. We conclude that higher local revenue autonomy reduces income inequalities within localities, which effect differs between the type of revenue and jurisdiction considered. Chapter 3 analyzes the impact of the transfers from central government to municipalities on the revenue mobilization by municipalities. Our results show that increasing central transfers to subnational government boost revenue mobilization by municipalities for both tax revenue and non-tax revenue. The effect of transfers is found to be higher for tax revenue than for non-tax revenue. Finally, we examine whether the effect of government responsiveness on property tax compliance differs between central government and municipalities in chapter 4. The results conclude that responsiveness by municipalities is found to have a greater effect on property tax compliance than those by central governments. The results of our analysis bear important policy implications to strengthen public sector, especially in sub-Saharan Africa.

Cette thèse de doctorat étudie, dans un cadre théorique, l’incidence des politiques fiscales environnementales au regard de l’hétérogénéité des travailleurs. Elle analyse la construction de politiques fiscales en fonction de trois objectifs : réduire les émissions de pollution, améliorer l’efficacité, et réduire les inégalités. Cette thèse est constituée d’une introduction et de trois chapitres (articles académiques) qui chacun décline cette question sous différents aspects. Le premier chapitre s’intéresse aux choix éducatifs et analyse l’impact des taxes environnementales sur l’efficacité et l’équité au travers ces choix d’éducation. Le second chapitre se concentre sur l’impact des taxes environnementales dans un contexte d’imperfection du marché du travail (chômage involontaire frictionnel). Le troisième chapitre est consacré aux disparités régionales en matière de salaire, d’emploi et de préférence pour les biens polluants. / This Ph.D. dissertation studies the incidence of environmental taxation between heterogeneous workers. In a theoretical framework, it analyses the design of environmental fiscal policy in regards with three competing goals : reducing emissions, improving economic efficiency, and limiting economic inequality. It consists of an introduction and three chapters (essays), each of them focusing on a different aspect of the problem. The first chapter uses a model with endogenous education and looks at how environmental taxation can affect efficiency and equity through its effects on educational choices. The second chapter focuses on the impact of green taxes on inequalities and unemployment using a search-friction model. The third one deals with regional disparities in regards with unemployment, wages and preferences.

SARAs have been established to achieve dual objectives of improving efficiency and controlling corruption in tax administrations. Key question for this research include: why some SARAs have failed to effectively control opportunities for corruption and what should be done about it? To explore these questions, this thesis has set out an Anti-Corruption SARA Framework. The novel contribution of this thesis lies in developing the new lens (analytical framework) which causes us to see the topic of SARAs against corruption quite differently (due to differentiating between motivations and opportunities for corruption). In order to analyze the validity of the framework, a two-staged analysis of SARAs, labelled as the macro and micro analysis, was conducted for SARAs and Federal Board of Revenue (FBR) in Pakistan. In the macro level of analysis (through secondary literature analysis), it was found that SARAs made partial progress to control corruption by focusing more on controlling motivations for corruption (through personnel autonomy) and lesser focus on controlling opportunities for corruption (through effective accountability). In the micro analysis (through semi-structured interviews and secondary literature), it was found that FBR remained ineffective in controlling both motivations and opportunities for corruption despite focusing more on controlling motivations for corruption (through personnel autonomy) and lesser focus on controlling opportunities for corruption (through effective accountability). In both macro and micro analyses, continued interference from Ministries of Finance (MoF) was found to undermine not only effective accountability for SARAs and FBR, but also undermining control of opportunities for corruption. Findings of both macro and macro level of analysis resulted in three main recommendations. These findings pointed towards a recommendation of reforming SARAs into an organizational form which is far more disaggregated from the parent ministry, such that SARAs have no accountability link with MoFs in the presence of other effective oversight bodies. It is recommended that SARA countries should develop this understanding about importance of balancing both autonomy and accountability mechanisms to be fully effective against corruption for controlling both motivations and opportunities for corruption. Thirdly, research findings point towards a case of converting FBR into a SARA in the form of Pakistan Revenue Authority, such that it is free from any direct oversight by the MoF, and in contrast should be subjected to effective oversight by other oversight bodies, such as already existing Cabinet Committee for Federal Revenue.

La question du développement inclusif dans les pays en développement est au cœur de cette thèse. Cette dernière s'articule autour de quatre chapitres sur les questions de politique fiscale et les questions liées à la croissance inclusive. Le chapitre 1 explore comment la politique fiscale de l’Etat affecte l'inclusivité de la croissance dans les pays en développement. Nous observons que la politique fiscale affecte la croissance inclusive de manière significative si et seulement si les pays ont de fortes qualités institutionnelles. En outre, notre résultat montre qu'il existe un seuil optimal au-delà duquel toute augmentation du taux d'imposition négativement la croissance inclusive. Le chapitre 2 examine les effets des composantes des dépenses publiques sur l'équité et la croissance dans les pays d’Afrique subsaharienne, notamment s'il est possible de concevoir des dépenses publiques en vue de promouvoir une société plus équitable sans sacrifier la croissance économique. Notre étude a permis de montrer que l’investissement en infrastructure a contribué à une croissance plus inclusive en Afrique subsaharienne que d'autres dépenses publiques. Ces résultats suggèrent que des programmes temporaires et bien ciblés devraient être mis en place pour aider ceux qui sont laissés pour compte par le processus de croissance. Le chapitre 3 cherche à savoir si les problèmes d’inégalités de revenus se sont posés ou non dans les périodes d'ajustement budgétaire en Côte d'Ivoire au cours de la période 1980-2014. Nos résultats montrent une amélioration de la performance de croissance après les épisodes de consolidation budgétaire, mais aussi des diminutions de l'écart de revenu dans les périodes suivantes les années d’ajustements budgétaires. Enfin, le chapitre 4 évalue la crédibilité des prévisions budgétaires et leurs effets sur le bien-être social dans les pays de la CEMAC et de l'UEMOA. Nous sommes aboutis aux résultats que l'inefficacité des prévisions budgétaires se produit dans la plupart des cas parce que les erreurs de prévisions sont proportionnelles à la prévision elle-même, mais aussi parce que les erreurs passées sont répétées dans le temps. En outre, une partie des erreurs de prévision des recettes peut s'expliquer par des chocs aléatoires survenus dans l'économie. Par conséquent, ces erreurs dans les prévisions de revenus considérées comme des chocs de politique budgétaire ont un effet négatif sur la croissance inclusive. / The issue of inclusive development in developing countries is at the heart of this thesis. The latter revolves around four chapters on fiscal policy issues and inclusive growth-related matters. Chapter 1 explores how government tax policy affects the inclusiveness of growth in developing countries. Evidence is shown that tax policy affects significantly inclusive growth if and only if the countries have a strong institution quality like low corruption and a good bureaucratic policy. In addition, our result shows that there is an optimal tax beyond which, any increase in the personal income tax rate should have negative impact on inclusive growth. The Chapter 2 examines the effects of government expenditure components on both equity and growth in sub-Saharan countries, especially whether it is possible to design public spending to promote a more equitable society without sacrificing economic growth. We find that investment in infrastructure contributed to more inclusive growth in Sub-sub Saharan African economies than others government spending. These results suggest that temporary and well-targeted programs should be implemented to help those being left out by the growth process. The Chapter 3 investigates whether income inequality matters in the periods of fiscal adjustments in Côte d’Ivoire over the period 1980-2014. The results show an improvement in growth performance after fiscal consolidations episodes, but also income gap decreases in the periods ahead fiscal adjustments. Lastly, Chapter 4 assesses the credibility of fiscal forecasts and their social effects in CEMAC and WAEMU countries. We obtain evidence that the inefficiency of fiscal forecast occurs in most time because the forecast deviation is proportional to the forecast itself, but also because the past errors are repeated in the present. Furthermore, a part of revenue forecast errors can be explained by random shocks to the economy. Therefore, these errors in revenue forecast considered as fiscal policy shocks has a detrimental effect on inclusive growth.