Omar SENE

        Post-Doctoral Researcher

                Affiliation Ecole Polytechnique

             Address: 91128 Palaiseau Cedex, FRANCE
                  E-mail: omar.sene@polytechnique.edu


Social capital
- Health - Education - Applied Econometrics - 
Field Experiments 

September 2015 - Present:          Post-Doctoral Research Fellow, Ecole Polytechnique                                                                                                                                                
October  2014 - August 2015:      Post-doctoral Research Fellow, EconomiX, University Paris 10, Nanterre
May 2014
 - July:                        
Research Assistant, University Paris Sud
Nov 2013-May 2014
Post-doctoral Research Fellow, CNRS - Centre d'Economie de la Sorbonne
Sept 2011- Aug 2013:                   ATER University Paris 1, Pantheon Sorbonne
2009-2010 :                                  Teaching assistant, University Gaston Berger

2008 :                                            Field Survey Supervisor in Senegal                           

2009-2013 - PhD, Paris School of Economy - University Paris 1, Pantheon Sorbonne
Title:           "Social Capital, Trust and Provision of Local Public Goods"
Supervisor: Guillaume Hollard
Louis-Levy Garboua,Yann Algan, Jean-Marie Baland, Juan-Camilo Cardenas, Margherita Comola, 


The ability of communities to engage in collective action (e.g. by maintaining health facilities) and promote the relevant social norms (e.g. introducing sound hygiene practices) would appear to be crucial for health improvements in developing countries. This ability is often referred to as social capital. Intuition suggests that communities endowed with more social capital should be better able to provide local health services, all else being equal, suggesting a causal relation between social capital and health. We thus here test for a causal role of social capital, as measured by self-reported trust, in determining access to basic health facilities in sub-Saharan Africa. 
To skirt the reverse-causality problems between social capital and basic health, we rely on instrumental-variable (IV) estimates. Using Afrobarometer data, we find that a one standard-deviation increase in trust is predicted to lead to a 0.22 standard-deviation fall in doctor absenteeism, a 0.31 standard-deviation fall in waiting time and a 0.30 standard-deviation fall in bribes. As a robustness check, we also use a different database (DHS) regarding a different health issue, access to clean water. We find that a one standard-deviation rise in trust leads to a 0.33 standard-deviation rise in access to clean water. 
We find a large causal impact of social capital on the provision of health related local public goods. The variety of public goods considered provides insights about the possible channels through which social capital is converted into health improvements.

On October 12th, 2009 Elinor Ostrom received the Nobel Prize in Economics for her analysis of the commons. This article presents a survey of her work. We shall begin by redrawing the academic route of Ostrom. In the second part, we show how she successively used various methods of investigation throughout a route which leaves the meticulous study of multiple concrete situations to evolve towards the design of public policies for big international bodies. The conclusion describes the implications she draws from her work so as to contribute to a renewal of rational choice theory.


Working Papers

This paper investigates the extent to which different measures of trust are connected to a community's ability to undertake collective action.   The objective is to clarify what trust measurement method is better at explaining how heterogeneous individuals manage to engage in joint activities, despite the associated problem of free-riding. For this purpose, we use a version of the Trust Game in which subjects are matched with a random anonymous member of their own community. Results are compared to survey trust questions: the World Value Survey trust question and specific questions regarding trust in neighbors and trust in strangers. We find that trust, as measured by survey questions, has poor predictive power, while the results from a simple trust game are much better predictors of local participation in collective activities. More particularly, a one-unit change in the amount sent increases the probability of participation in Tontine, Credit Association and Animation respectively by 6%, and 3%. Furthermore, we find that individuals who consider that "most people can be trusted" have 17.58% more chance to participate in Animation activities.

Because of limited governmental resources, communities in Africa often rely on collective action to provide basic public goods such as schools. What drives the ability of communities to produce better schools? Two important lines of research shaped our understanding of the ability of communities to engage in collective action. The first line proposes ethnic division as a key determinant, with more ethnically heterogeneous countries having lower economic performances and levels of public goods. Thus, we expect to find better schools where ethnic fractionalization is low. The second line of research focuses on social capital as a major determinant of the ability to engage in collective action. We expect that trust among community members, a widely-used measure of social capital, is an important and positive determinant of school quality.

     The present work aims to disentangle the relative effects of ethnic fractionalization and social capital on school quality. We use instrumental variable estimations to address reverse causality and other endogeneity issues. We instrument both social capital and ethnic fractionalization by using historical information on the settlement patterns of ethnic groups in Sub-Saharan Africa. Our empirical strategy is implemented by combining four datasets, including Afrobarometer, covering 16 sub-Saharan countries.

       We find an important and positive effect of trust on the practical aspects of schooling, such as maintaining buildings or providing textbooks. A one percent increase in the  level of trust increases the quality of local public goods by 0.18 to 1.05 percent, depending on the measure of school quality under consideration. In sharp contrast, ethnic fractionalization is found to have a very limited effect, if any. Our results suggest that policies designed to enhance social capital are likely to have a positive effect on schools and local public goods in general.

Works in progress

  • "Improving Students' Performance: Evidence From a Field Experiment" (2015) with (Mahmoud Farrokhi-Kashani, Guillaume Hollard)

 We use a field experiment to evaluate the effect of providing relative performance feedback on performance under tournament incentives. Our subjects are girls aged 14 studying in single-sex schools in Iran. We find that, in a real competition in a natural environment, feedback improves the performance of both low- and high-ability students. In addition it helps students to perform more efficiently by decreasing their mistakes.

  •  "Using Latent Trait Approach to Measure Trust and Predict Behavior in Experiments" (2015)

In this paper, I use an original mixture of survey and experimental data on trust from four villages in Senegal to compare  trust, measured as a latent personality trait to the trusting behavior in experiments. To do so, I first construct a score based on both individual responses and the properties of the question asked in order to pick up each individual's latent trait. The validity of this measure is assessed by establishing the extent to which it predicts experimental behavior. I find a positive and significant relationship between survey trust and trust behavior in experiments.


Ecole Polytechnique: 2015-2017

2015 - 2016  - PC Econometrics  (M1)

University Paris I, Pantheon-Sorbonne: 2011-2013

2012 - 2013 T.A. Econometrics (L3)
2012 - 2013 T.A. Microeconomics (L1).
2011 - 2012 T.A. Statistics (L3)

University of Saint-louis: 2008-2010

2009 - 2010 T.A. Macroeconomics (Mass 2) .
2009 - 2011 T.A. Microeconomics (L3).
2008 - 2009 T.A. Microeconomics (L1)