PhD Defence: Nourat Guigma

Nourat Guigma 
CERDI, Université Clermont Auvergne 

Examiners

Bertrand Laporte, Professor, Université, Clermont Auvergne, France
Jamel Saadaoui, Professor, Université Paris 8, France
Relwendé Sawadogo, Professor, Université Joseph Ki-Zerbo, Burkina-Faso
Hakim Hamadi, Acting Head of the Capacity Building and Outreach Division, OCDE, France
Grégoire Rota-Grasiozi, Professor, Université, Clermont Auvergne, France
Emilie Caldeira, Associate Professor, Université Clermont Auvergne, France

Abstract

This thesis investigates how developing countries can preserve their fiscal sovereignty and effectively mobilize domestic resources in the face of tax base erosion. It identifies and analyzes the main mechanisms driving this erosion, particularly in connection with the digitalization of the economy and globalization, while assessing the effectiveness of international tax cooperation frameworks implemented to address these challenges. To do so, we conduct policy-oriented research using appropriate statistical and econometric tools and propose economic policy recommendations for developing countries. The first part analyzes the mechanisms of tax base erosion by identifying the main channels used to artificially reduce tax liabilities (Chapters 1 and 2). In Chapter 1, we examine the impact of Double Taxation Treaties (DTTs) on foreign direct investment (FDI) flows, distinguishing between real and phantom investments. We find that while DTTs increase real FDI, they also significantly stimulate phantom investments, especially in developing countries and tax havens. These robust results, confirmed across various estimators and control variables, highlight DTTs as a channel of base erosion and stress the urgency of reforming tax treaties to foster real investment while ensuring sustainable economic growth. Chapter 2 explores the relationship between mobile money adoption and money laundering risks in developing countries. We find that mobile money adoption increases the risk of money laundering. A detailed analysis of different services indicates that Peer-to-Peer (P2P) transfers and cash-out services contribute disproportionately to this risk. While Government-to-Person (G2P) transfers can mitigate short-term risks due to improved traceability, other services such as international remittances and bulk payments exacerbate vulnerabilities. These findings underscore the need for robust regulatory frameworks, strengthened technological safeguards, and enhanced international cooperation to mitigate these risks while preserving financial integrity. The second part of the thesis focuses on the effectiveness of international tax cooperation mechanisms in curbing tax base erosion (Chapters 3 and 4). Chapter 3 analyzes the impact of information exchange reforms on tax revenue mobilization in developing countries, finding that such reforms significantly increase tax revenues. Chapter 4 evaluates the effects of Exchange of Information (EOI) for tax purposes on investment flows from developing countries to offshore financial centers. Our results show a significant decrease in active offshore entities following the implementation of EOI, suggesting that increased transparency and compliance costs discourage the creation of offshore structures. However, our analysis of FDI and portfolio flows shows that EOI does not significantly curb the overall volume of cross-border capital flowing from developing countries to offshore jurisdictions. This indicates that while EOI limits the creation of offshore entities, it does not fully constrain capital mobility through other offshore channels.To enhance the effectiveness of these reforms, countries should strengthen cooperation between developed and developing nations in order to better monitor cross-border financial flows.

Keywords

Tax base erosion, Resource mobilization, Development financing, Digitalization, Globalization, Fiscal sovereignty, Tax cooperation, Impact analysis, Foreign direct investment, Phantom investment, Real investment, Offshore financial centers, Money laundering, Tax transparency, Tax optimization, Harmful tax competition, Financial inclusion, Mobile money, International tax governance, International tax reforms.

https://theses.fr/s363218