Three essays on the role of income fluctuations for the macroeconomy[Trois essais sur le rôle des fluctuations de revenu dans la macroéconomie]

This thesis investigates the complex dynamics of income fluctuations and theirimplications for welfare and economic stability through three interconnected essays. Thefirst chapter examines how monetary policy influences firms' inventory decisions via thecost-of-carry channel. It posits that rising interest rates increase carrying costs, promptingfirms to lower prices to manage inventories, thereby affecting inflation dynamics. Byintegrating firm heterogeneity and idiosyncratic demand shocks into an inventory model,the chapter elucidates how these decisions aggregate to impact the broader economy,particularly during periods of high inventory levels.The second chapter shifts focus to the variation in fiscal systems, specifically SocialWelfare Functions (SWFs) in France and the U.S. Utilizing a Bewley-type model, thestudy estimates SWFs that reflect social preferences and identifies a stark contrast: the U.S.SWF favors high-income individuals, while the French version supports low-incomehouseholds. This analysis highlights the role of social preferences in shaping fiscal policiesand their implications for inequality. The final chapter explores the relationship betweenfood price shocks and the debt servicing capacity of low-income countries. It argues thatrising prices for essential food commodities increase the risk of sovereign default for thesenations, particularly those reliant on imports. By employing an instrumental variableapproach and a case study of Ghana, the chapter demonstrates how food price shocks canexacerbate economic distress and debt risks, underscoring the need for internationalsupport. Overall, the essays collectively enhance understanding of how monetary policy,fiscal systems, and global trade dynamics interplay to influence income fluctuations,providing critical insights for policymakers and economists.