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My name is pronounced: Day-vee Wex

Welcome! I am a fifth-year Ph.D. student in the Department of Economics at the Massachusetts Institute of Technology (MIT). My research is in development economics and organizational economics, focusing on technology and firms in lower-income countries, particularly in West Africa.

My dissertation explores how digital technologies reshape economic relationships and contract structures within and between firms, and uncovers the key drivers and barriers to their adoption.

Over the past eight years, I have conducted research projects in Côte d'Ivoire, Ethiopia, Senegal, and Togo.

I am on the 2024-25 Academic Job Market. [CV] - houeix@mit.edu

Working Papers

  1. Asymmetric Information and Digital Technology Adoption: Evidence from Senegal (Job Market Paper), Draft Coming Soon
    Abstract

    I combine two field experiments, guided by contract theory, to study how digital technologies can alleviate information asymmetry and reshape contracts within firms. While these technologies can reduce moral hazard by making data observable to employers, they may also deter adoption by employees who are concerned about losing informational rent. I explore this trade-off through the expansion of digital payments in the Senegalese informal taxi industry. In the first experiment, I randomized access to a digital payment technology for 1,891 drivers, and within this group, I further randomized the degree to which transactions were observable by employers in a panel of 613 taxi owner-driver relationships. I find that digital payments benefit drivers and serve as effective monitoring tools for taxi owners. Enhanced transaction observability increases worker effort, shifts contracts towards salaried employment, and reduces turnover. However, I observe differential adoption among workers: 50% of drivers — primarily the least productive and poorest — refused to adopt when observability was an option. The second experiment reveals that assuring these drivers that digital transactions would remain undisclosed to owners nearly doubles adoption rates. I use these experimental variations to estimate a theoretical framework and analyze the impact of policy counterfactuals on welfare, such as mandating technology adoption or removing observability embedded in payments. My findings highlight the trade-off between transparency and the adoption of digital technologies, emphasizing the need for policymakers and innovators to consider distributional impacts to broaden adoption and enhance small firm growth.

  2. Nationwide Diffusion of Technology Within Firms’ Social Networks, Draft Coming Soon
    Abstract

    I conduct a randomized experiment to study nationwide technology diffusion of a new digital payments technology in Senegal. By leveraging two novel sources of network data - mobile money transactions and anonymized phone contact directories covering the near universe of the adult population in Senegal - I identify three sets of spillovers from taxi firms randomized to receive early access to the technology: to other firms within the taxi industry; to other industries; and to other cities. I show that spillovers go beyond strategic complementarities, reflecting social learning facilitated by social ties and remote interactions.

  3. Relational Frictions Along the Supply Chain: Evidence from Senegalese Traders (with Edward Wiles), Draft Coming Soon
    Abstract

    Search and trust frictions have historically hindered the ability of small firms to access foreign input markets. We run a field experiment with 1,862 small garment firms in Senegal, in which we provide exogenous variation in search and trust frictions of interacting with suppliers in Turkey. Our search treatment connects firms to new suppliers using social media, and our two trust treatments vary the information about the types and incentives of these suppliers. To measure the impact on foreign market access, we mystery shop at all firms. Treated firms are 25% more likely to have the varieties the shopper requests and the goods supplied are 32% more likely to be high quality, driven by the search treatment. However, the trust treatments matter for longer-term outcomes: trust-treated firms are significantly more likely to develop these connections into relationships that persist beyond the study. These new relationships lead to increases in profit and sales, particularly among wholesalers.

  4. Financial Inclusion and Rural Electrification: Evidence from Togo (with Paul Brimble, Axel Eizmendi Larrinaga, and Toni Oki), Draft Coming Soon
    Abstract

    Despite recent advancements, most people in sub-Saharan Africa still lack electricity. While rural electrification has garnered policy attention, recent academic literature estimates low demand. We argue that high transaction and transport costs for paying electricity bills - a critical friction faced by rural households - partly explain this puzzle and weaken policy effectiveness. We examine the scattered rollout of two nationwide policies in Togo in 2019 to support this claim: a subsidy program for solar home systems and an expansion of mobile money agents. The subsidy, which nearly halved the price, doubled adoption rates, primarily among customers near mobile money agents. These customers could reduce their payment frequency and buy in bulk, due to lower baseline transaction costs. The follow-up mobile money agent expansion reduced transaction costs directly, leading to a decrease in payment frequency due to a large income effect. In this setting of high liquidity constraints, the ability to buy in bulk outweighed the benefits of cheaper consumption smoothing. Our findings highlight the complementary role of subsidies and financial inclusion in increasing access to essential services.

  5. Eliciting Poverty Rankings from Urban or Rural Neighbors: Methodology and Empirical Evidence (with Pascaline Dupas and Marcel Fafchamps), Revised August 2024 for Quantitative Economics
    Abstract | PDF

    We introduce a novel approach for eliciting relative poverty rankings that aggregates partial orderings reported independently by multiple neighbors. We first identify the conditions under which the method recovers more accurate rankings than the commonly used Borda count method. We then apply the method to secondary data from rural Indonesia and to original data from urban Cote d’Ivoire. We find that the aggregation method works as well as Borda count in the rural setting but, in the urban setting, reconstructed rankings from both the pairwise and Borda count methods are often incomplete and sometimes contain ties. This disparity suggests that eliciting poverty rankings by aggregating rankings from neighbors may be more difficult in urban settings. We also confirm earlier research showing that poverty rankings elicited from neighbors are correlated with measures of poverty obtained from survey data, albeit not strongly. Our original methodology can be applied to many situations in which individuals with incomplete information can only produce a partial ranking of alternatives.

Selected Work in Progress

  • Digitalization of Local Tax Collection in Côte d’Ivoire (with Pascaline Dupas)

Other Publications