Competing providers as complements: Demand for prepaid mobile plans in Burkina Faso Job Market Paper

Draft

Prepaid pay-as-you-go plans are widely used worldwide and are especially popular in emerging countries. The literature highlights that the contract flexibility associated with this type of plan, the off-net service overcharges, and recurring provider price discounts make it interesting for consumers to subscribe to multiple providers. However, this joint consumption contrasts with the exclusivity expected when products are supplied by competing firms. In emerging economies, consumers often subscribe to multiple competing mobile service providers, i.e they multi-sim. This observation contrasts with the substitution patterns typically expected between competing firms and has important implications for price competition and consumer welfare. This paper quantifies the welfare gains from multi-simming using a 2020 survey of 1,899 subscribers in Burkina Faso. In my sample, 60\% of consumers subscribe to multiple providers. Conditional on subscribing to multiple providers, they tend to spread their services across providers by pairing some services with specific providers. I estimate a discrete-continuous choice model of provider and service-usage decisions, flexible enough to identify the gains from multiple subscriptions and the complementarity or substitutability across services conditional on subscriptions. My results indicate that within a provider, internet and communication (voice and text) are substitutes. I also find substantial, heterogeneous gains from multi-simming. My counterfactual analysis shows that consumer surplus would have been 49.2\% lower without multi-simming. Because consumers respond to price changes by choosing, service by service, which provider to use, multi-simming intensifies price competition and reduces firms' market power. I find that this price-related effect accounts for 8\% of the welfare gains, while 92\% comes from choice set expansion. I also find that the gains are larger for women, less educated, older users, and in lower-quality markets. This suggests that multi-simming helps mitigate digital divides.

Presented at: Women in Econometrics Conference (Poster, 2026) · Congrès SCSE (2026)· CIREQ PhD students'conference (2026) · Competition Bureau of Canada (Invited Seminar, 2025) · Association des femmes scientifiques africaines (2025)

Estimation of demand with decreasing block pricing and market-level data

Draft

Discrete-continuous choice models (DCC) are commonly used to estimate demand for products with decreasing/increasing block rates. Standard estimation methods for DCC models require individual-level consumption data, which is not always readily available. Using the pure characteristics model of Berry and Pakes (2007), I propose a discrete-continuous choice model to estimate demand for products with block rates. The idea is to use block market shares and characteristics to recover consumers' preferences. I apply this method to estimate demand for natural gas in Quebec. This paper also proposes new instruments inspired by the interesting institutional background. I found conditional and unconditional price elasticities close to previous estimates in the literature.

Presented at: Competition Bureau of Canada (Invited Seminar, 2025) · Congrès SCSE (2025) · CIREQ Econometric Conference (Poster, 2025) · CESG Annual Meeting (Poster, 2024)