Carolina Tojal R. dos Santos

Welcome to my website!

I am a  research economist at the Inter-American Development Bank (IADB) .

I hold a Ph.D. in Economics from the University of Michigan

My research fields are Industrial Organization and Environmental Economics. 

Here is my CV.

Email: ctsantos@umich.edu

Research 

with Bruna Guidetti

This paper investigates strategies to expand piped water and sewer through private providers. Using billing data from a major provider in Brazil and a structural model of consumer sanitation demand and service expansion, we assess the viability of connection targets and the welfare effects of connection subsidies and price incentives. We find that universal connection targets are largely unfeasible due to low sewer take-up. Combining connection subsidies with higher sewer prices boosts expansion and adoption but requires government funding. Charging consumers upon sewer availability is self-sustaining, promotes adoption and expansion but shifts costs to households.

with María Pérez-Urdiales

Latin America and the Caribbean (LAC) countries have made notable progress in reducing income inequality; however, the extent to which water and sanitation may foster inequalities remains unclear. In this sector, disparities emerge as lower-income households may encounter reduced access to clean water, utilize less water, or bear a disproportionately higher financial burden than higher-income households. In this paper, we investigate latter source of inequality in the water and sanitation sector in LAC. We analyze and compare inequality measures for water expenditures and income for Brazil, Colombia, Costa Rica, and Uruguay using survey data from the Americas Barometer of the Latin American Opinion Project (LAPOP). Our descriptive analysis indicates that low-income households allocate a larger proportion of their income to water expenditures compared to high-income households. By comparing the water concentration curve to the Lorenz curve for each country, we find that water expenditures are generally more equitably distributed than income, leading to an unequalizing effect, as households spend similar amounts regardless of income level. Additionally, we demonstrate that total water expenditures, encompassing tap water, bottled water, and water delivered by trucks, align more closely with income distribution than tap water alone in Brazil, Costa Rica, and Uruguay, whereas the opposite is true for Colombia. These disparities may be attributed to water tariff subsidies and the higher consumption of bottled water among wealthier households.

This paper investigates the impact of direct-to-consumer advertising (DTCA) on women’s decisions regarding prescription contraceptives. I use television advertisement data and claims data, applying the Border Approach proposed by Shapiro (2018) to estimate the causal effects of television ads. My findings indicate that a 10% increase in DTCA for short-term contraceptive methods, such as pills, increases demand for the advertised product by 2.7% but also generates positive spillover effects on other branded and generic products within the same category. Conversely, these ads reduce the demand for Long-Acting Reversible contraceptives (LARCs), such as IUDs and implants, leading to a substitution towards short-term methods.

with Ying Fan and Christopher Sullivan

This paper provides a theoretically founded empirical model to simultaneously investigate firm competition and estimate markups. The model nests the standard oligopoly model, but also allows for firm collusion. Different from conduct parameter models, our model is consistent with a series of theoretical models. We show that a nonparametric marginal cost function can be identified, which gives an estimate of markups. Through Monte Carlo simulations, we show that our approach works better in estimating markups than a standard oligopoly model or a conduct parameter model.