publications | Olivia Bertelli

Journal Articles

2026

Inter-Group Cooperation and Conflict. Experimental Evidence From Yemen

Olivia Bertelli and Sikandra Kurdi

Oxford Bulletin of Economics and Statistics, 2026

[Rang A classement HCERES 2023]

Abs DOI

This study investigates pro-sociality among individuals during an ongoing war. We focus on Yemen, where the recent large-scale conflict has divided the country geographically, putting different regions in opposition with one another. We collect original survey data and develop a mobile phone-based version of a public good game to allow participants from regions on opposite sides of the conflict to play in pairs across the entire country. Participants play two games: one with an in-group partner (from the same region) and one with a randomly assigned partner from a different region—either from the antagonistic out-group (opposite conflict side) or from the non-antagonistic out-group (same conflict side). We further merge our data with the Armed Conflict Location and Event Data Project (ACLED) conflict data to explore whether conflict intensity affects participants’ behaviours in the games. Our results show a lower level of cooperation with the rival out-group compared to the non-rival out-group, along with higher in-group cooperation among participants heavily exposed to the war. Further results show that lower pro-sociality towards the rival out-group is mostly found among players from the North of Yemen, where sectarian identity is most clearly tied to the conflict division, and this effect is exacerbated by the intensity of conflict exposure. These results provide some of the clearest empirical support to date for concerns about the destruction of inter-group cooperation during an ongoing war.

2025

Does the Number of Children Affect Parental Participation? Evidence from an Education Campaign in Nepal

Florence Arestoff, Olivia Bertelli, Elodie Djemai, and 2 more authors

Revue d’économie du développement, 2025

[Rang B classement HCERES 2023] Forthcoming
Female Genital Mutilation: An Analysis of Potential Reporting Biases

Olivia Bertelli, Mathilde Lesueur, and Sandrine Mesplé-Somps

Revue d’économie du développement, 2025

[Rang B classement HCERES 2023] Forthcoming
Measuring insecurity-related experiences and preferences in a fragile state: a list experiment in Mali

Olivia Bertelli, Thomas Calvo, Emmanuelle Lavallée, and 2 more authors

World Development, 2025

[Rang A classement HCERES 2023]

Abs DOI

Measuring behaviors and preferences in times of conflict is of great interest for understanding conflict dynamics and designing conflict-resolution interventions. Yet, data users often cast doubts on the reliability of sensitive self-reported measures, especially in fragile contexts. We study sensitive experiences and preferences related to insecurity in a fragile State–Mali–by explicitly addressing potential response biases using a List Experiment (LE) method. We survey 1,500 individuals across the entire country and randomly assign respondents to answer sensitive questions through the LE or direct questions (DQ) techniques to measure response biases. We focus on three experience-related items (physical assault victimization, firearms’ possession, willingness to engage in violence) and two preference-related items (support for the military regime and trust in foreign armed forces in Mali). Results show significant biases affecting responses about preference-related items. Our analysis confirms that popular support for the military regime and mistrust in the foreign armed forces are large, but suffer from a substantial overestimation. Misreporting is not uniformly distributed across the population, but varies depending on gender, education and conflict exposure. Further results suggest that such heterogeneity in response bias can yield fake significant correlations between individual characteristics and sensitive items’ prevalence rates depending on the survey technique used.
What one thinks, what one says and what one does: male justifications and practices of gender-based violence in Mali

Olivia Bertelli, Thomas Calvo, Emmanuelle Lavallée, and 2 more authors

Journal of Development Economics, 2025

[Rang A classement HCERES 2023]

Abs DOI

Gender-based violence (GBV) is widespread across the world. While the majority of the literature focuses on women as the victims of GBV, this paper studies men’s justifications for and perpetration of GBV in Mali, one of the countries with the highest GBV prevalence rates in the world. We elicit the prevalence of eight GBV-related opinions and behaviors among men in Bamako, the capital city, by administering a set of list experiments that we compare to a set of direct questions to estimate response biases. We find large support for GBV: nearly one respondent in two supports female genital mutilation or intimate partner violence. Besides, one in four has already physically hit an adult woman. Our results also show that several questions suffer from significant response biases when asked directly. Support for female genital mutilation is overreported, with actual approval being lower than openly stated. Conversely, justification of intimate partner violence is underreported, likely due to social pressure against it. While response bias varies little with respondent characteristics, prevalence rates are systematically lower among men with a secondary level of education. Our results are in line with response bias being shaped by the legal framework addressing GBV as well as prevailing social norms, highlighting the need for caution when using data collected through direct questioning.

2024

Men’s justification of intimate partner violence: results from an experimental survey in Mali

Olivia Bertelli, Thomas Calvo, Massa Coulibaly, and 5 more authors

Revue d’économie du développement, 2024

[Rang B classement HCERES 2023]

DOI
Reaching out to socially distant trainees: experimental evidence from variations on the standard farmer trainer system

Olivia Bertelli and Fatou Fall

European Review of Agricultural Economics, 2024

[Rang A classement HCERES 2023]

Abs DOI

The farmer trainer (FT) model has gained momentum as a cost-effective alternative to traditional agricultural extension systems. However, there may be friction in the transmission of information, whereby farmers closer to the FT may benefit more than socially distant farmers. This study explores whether variations on the standard FT model facilitate the diffusion of information outside the FT’s pre-existing social network. On top of a standard FT training, a sub-sample of voluntary FTs in rural Uganda was randomly assigned to receive (i) vouchers for accessing professional extension agents, (ii) a signpost advertising the trainer services or (iii) further training aimed at tailoring the training to the specific needs of the trainees. The results show that the FTs assigned these treatment variations trained more farmers, a larger proportion of whom belonged to the FT’s own close circle. The FTs who received vouchers were the only ones to reach out to more socially distant farmers and were also those who organized the most training sessions. We show that these effects are independent of any FT prominence in the village. Nevertheless, further evidence suggests exercising caution regarding the presence of friction in the transmission of knowledge, since knowledge and technology adoption appear to increase only among farmers closely connected to the FT.

2023

Collecting data on sensitive experiences and attitudes: a Malian case study

Olivia Bertelli, Thomas Calvo, Massa Coulibaly, and 5 more authors

Global Africa, 2023

Abs DOI

In standard household surveys, the data collected are exposed to response bias, particularly for questions considered sensitive. The List Experiment method is an alternative survey technique for limiting these biases. This article presents the results of an experimental survey conducted using this method with 1,509 individuals throughout Mali. Individuals were surveyed by telephone during the summer of 2021 about their experiences and political attitudes related to insecurity. From a methodological point of view, we have drawn a number of lessons from the survey: among others, a very good understanding and acceptability of the method by the respondents, due in particular to the quality of the interviewers and supervisors; the need for a more complex sample design than for a standard questionnaire; and the importance of a short questionnaire when surveying by telephone. From an analytical point of view, the survey reveals the existence of significant social desirability biases - particularly for questions concerning political attitudes in relation to insecurity.

2022

Expériences et opinions liées à l’insécurité: une analyse des biais déclaratifs au Mali

Olivia Bertelli, Thomas Calvo, Emmanuelle Lavallée, and 2 more authors

Revue d’économie du développement, 2022

[Rang B classement HCERES 2023]

DOI

2019

Food Security Measures in Sub-Saharan Africa. A Validation of the LSMS-ISA Scale

Olivia Bertelli

Journal of African Economies, 2019

[Rang B classement HCERES 2023]

Abs DOI

Despite the international community’s emphasis on the need to achieve food security, there is still much debate surrounding its measurement, due mainly to its multidimensional aspects. This paper investigates the capacity of a new type of measure, food security scales, to capture dimensions of food security that other measures, such as food expenditures, caloric availability and food diversity, may miss. Drawing on nationally representative household panel data from Malawi, Nigeria and Tanzania, I find that the scale is a useful complementary measure to standard measures. Cross-section and panel analysis shows that the scale provides further insights into food vulnerability and coping strategies characteristic of food insecurity, dimensions not captured by the standard measures.

Books

2026

Gender Economics in the Global South

Olivia Bertelli

2026

DOI

Unpublished

2025

Impact Evaluation of Parental Education Campaign on Child Development in Nepal

Florence Arestoff, Olivia Bertelli, Elodie Djemai, and 2 more authors

2025

DIAL Working Paper n.2025-07
Female Genital Mutilation Bans: Natural Experiments from 19 Countries

Olivia Bertelli, Mathilde Lesueur, and Sandrine Mesplé-Somps

2025

Unpublished
Empowering Girls in Mali. Evidence from the SWEDD program

Olivia Bertelli

2025

Unpublished
The Effects of Adolescent Girls and Young Women Clubs: Evidence from a Multi-Country RCT in West Africa

Olivia Bertelli, Othmane Boulhane, Claire Boxho, and 6 more authors

2025

Unpublished

2019

Impacts on trust and social capital of a youth employment program in Yemen: Evaluation of the rural and urban advocates working for development intervention for the Social Fund for Development

Olivia Bertelli, Sikandra Kurdi, M. Al-Maweri, and 1 more author

2019

Intl. Food Policy Res Inst, Vol. 24

DOI

2014

Food security and agriculture in developing countries: measurement and hypotheses for impact evaluations

Olivia Bertelli and Karen Macours

2014

FOODSECURE Working Paper n.21

Miscellaneous

2025

Understanding men’s true perspectives on gender-based violence in Mali

Olivia Bertelli, Thomas Calvo, Emmanuelle Lavallée, and 2 more authors

2025

VoxDev

2024

Granting equal access to information: experimental evidence from Uganda

Olivia Bertelli and Fatou Fall

2024

Dialogue n.73, p.2-14
Comment mesurer efficacement la sécurité alimentaire ?

Olivia Bertelli

2024

Dauphine Eclairages

2020

Measurement and observation of gender-based violence and conflict-related violence in developing countries

Olivia Bertelli, Thomas Calvo, Emmanuelle Lavallée, and 2 more authors

2020

Dialogue n.57 p.1-7