Publications (ordered by theme)
Land Property Rights
This paper explores the incentives for backyarding, an expanding category of urban land-use in developing countries that has proliferated South Africa. The theoretical model exposes the trade-off faced by the homeowner in deciding how much backyard land to rent out: loss of yard space consumption in return for a gain in rental income. Under common forms for preferences, the homeowner's own-consumption of yard space falls as land rent increases, causing more land to be rented to backyarders. With better job access for backyarders raising land rent by increasing their willingness-to-pay, the analysis then predicts that the extent of backyarding will be higher for parcels with good job access. This hypothesis is tested by combining a satellite-based count of backyard dwellings per parcel with job-access data. The empirical results are consistent with the prediction that better job access increases the extent of backyarding.
We analyze the joint dynamics of land property rights and urbanization, a key yet underexplored relation that underpins the process of economic development. Using a dynamic stochastic model of urbanization with endogenous demand for property rights over land use, we demonstrate that the costly provision of those rights may result in both residential informality that can persist over time and suboptimal urbanization whereby cities are too small and insufficiently productive. In developing countries, because land administrations in charge of issuing titles are difficult to reform, achieving the second best may require acceptance of some level of informality in spite of the negative externalities stemming from informal land tenure and informal settlements. This may not be easily implemented as urban elites may favor overall welfare-reducing policies that over-evict informal dwellers.
with Markus Goldstein, Kenneth Houngbedji, Florence Kondylis and Michael O'Sullivan, Journal of Development Economics, 2018, 132, 57-74.
We present evidence from the first large-scale randomized-controlled trial of a land formalization program. We examine the link between land demarcation and investment in rural Benin in light of a model of agricultural production under insecure tenure. The demarcation process involved communities in the mapping and attribution of land rights, cornerstones marked parcel boundaries and offered lasting landmarks. The tenure security improvement through demarcation induces a 23 to 43 percent shift toward long-term investment on treated parcels. We explore gender and parcel location as relevant dimensions of heterogeneity. We find that female-managed landholdings in treated villages are more likely to be left fallow—an important soil fertility investment. Women respond to an exogenous tenure security change by shifting investment away from relatively secure, demarcated land and toward less secure land outside the village to guard those parcels.
We review evidence regarding the size and evolution of the "land rush" in the wake of the 2007–8 boom in agricultural commodity prices, and we study the determinants of foreign land acquisition for large-scale agricultural investment. The use of data on bilateral investment relationships to estimate gravity models of transnational land-intensive investments confirms the central role of agro-ecological potential as a pull factor. However, this finding contrasts the standard literature insofar as the quality of the destination country's business climate is insignificant, and weak tenure security is associated with increased interest for investors to acquire land in the country. Policy implications are discussed.
with Rabah Arezki and Klaus Deininger, Economie et Statistique, 444-445, February 2012, 223-239.
Depuis la flambée des prix agricoles de 2007-2008, les médias se sont fait l’écho d’une « course aux terres » à l’échelle planétaire selon laquelle des pays importateurs de denrées alimentaires chercheraient à sécuriser leurs approvisionnements en acquérant de larges quantités de terres cultivables dans des pays en développement. Au-delà des comportements spéculatifs répondant à la fluctuation des prix mondiaux, les analystes voient dans ce phénomène une réponse à la pression démographique et à l’anticipation d’une hausse de la demande mondiale de produits agricoles amplifiée par l’évolution des revenus et modes de vie. Les enjeux pour le développement sont majeurs. Opportunité de développement d’un secteur agricole d’exportation ? Ou bien risque de pillage des terres au détriment des utilisateurs actuels, détruisant la petite agriculture familiale et exacerbant les risques environnementaux ?
Ce travail s’inscrit en amont de la problématique en cherchant à identifier les déterminants des investissements transnationaux qui s’accompagnent d’acquisitions de terres à grande échelle. En l’absence de base de données internationale et compte tenu de la difficulté de consolider les informations nationales, notre étude se base sur des informations publiées dans la presse internationale et la construction d’indicateurs adéquats de potentiel agro-écologique et de gouvernance foncière. L’estimation de modèles gravitaires utilisant ces variables montrerait une spécificité des investissements agricoles fonciers contrastant avec la littérature sur les investissements en général : alors que le rôle central du potentiel agro-écologique comme facteur d’attraction serait confirmé, les variables usuelles de gouvernance n’auraient aucun effet. Paradoxalement, les pays où les populations ne jouissent que d’une faible sécurité foncière apparaitraient même comme les plus attractifs, ce qui irait dans le sens des inquiétudes relayées par la presse et les organisations non gouvernementales.
This paper offers a new theoretical approach to urban squatting, reflecting the view that squatters and formal residents compete for land within a city. The key implication is that squatters "squeeze" the formal market, raising the price paid by formal residents. The squatter organizer ensures that squeezing is not too severe, since otherwise, the formal price will rise to a level that invites eviction by landowners. Because eviction is absent in equilibrium, the model differs from previous analytical frameworks, where eviction occurs with some probability. It also facilitates a general equilibrium analysis of squatter formalization policies.
Transport investments and policies
This paper assesses the relationship between access to markets and land cultivation in sub-Saharan Africa. Using a geo-referenced panel over four decades (1970–2010) during which the road network was significantly improved, we find a modest impact of improved market accessibility on local cropland expansion – especially in places that are exposed to better agricultural production conditions – as well as suggestive evidence of an increase in the local intensity of cultivation. Suggestive evidence of a positive association between improved market accessibility and local GDP growth beyond the impact of cropland expansion could reflect the stimulation of non-agricultural activities.
This survey reviews the current state of the economic literature, assessing the impact of transport investments and policies on growth, inclusion, and sustainability in a developing country context. It also discusses the specific implementation challenges of transport interventions in developing countries.
This paper analyzes the political economy of transport-system choice, with the goal of gaining an understanding of the forces involved in this important urban public policy decision. Transport systems pose a continuous trade-off between time and money cost, so that a city can choose a fast system with a high money cost per mile or a slower, cheaper system. The paper compares the socially optimal transport system to the one chosen under the voting process, focusing on both homogeneous and heterogeneous cities, while considering different landownership arrangements. The analysis identifies a bias toward underinvestment in transport quality in heterogeneous cities.
Residential segregation and spatial mismatch
This paper presents an impact evaluation of the French enterprise zone program which was initiated in 1997 to help unemployed workers find employment by granting a significant wage-tax exemption (about one third of total labor costs) to firms hiring at least 20% of their labor force locally. Drawing from a unique geo-referenced dataset of unemployment spells in the Paris region over an extensive period of time (1993–2003), we are able to measure the direct effect of the program on unemployment duration, distinguishing between short- and medium-term effects. This is done by implementing an original two-stage empirical strategy using individual data in the first stage and aggregate data and conditional linear matching techniques in the second stage. We show that although the enterprise zone program tended to “pick winners”, it is likely to be cost-ineffective. It had a small but significant effect on the rate at which unemployed workers find a job (which is increased by a modest 3%). This effect is localized and significant only in the short run (i.e. at best during the 3 years that follow the start of the policy).
Do spatial differences in unemployment duration reflect residential sorting or a true local effect? Focusing on the 1300 municipalities of the Paris region, we apply a methodology that disentangles individual and unspecified municipality effects. Estimating a proportional hazard model stratified by municipality and recovering a survival function for each municipality purged of individual observed heterogeneity, we show that local and individual characteristics add up in their contribution to unemployment duration. While only 30% of the spatial disparities in unemployment duration are explained by individual characteristics, 70% of the remaining disparities are captured by local indicators, mainly correlated with residential segregation.
This paper investigates the causal effects of the spatial organisation of Brussels on unemployment propensities. Using census data at the individual level, the unemployment probability of young adults is estimated while taking into account personal, household and neighbourhood characteristics. The endogeneity of residential locations is solved by restricting the sample to young adults residing with their parents; the potential remaining bias is evaluated by conducting a sensitivity analysis. The results suggest that the neighbourhood of residence significantly increases a youngster's probability of being unemployed, a result which is quite robust to the presence of both observed and unobserved parental covariates.
This article studies the effect of residential segregation and spatial mismatch (physical distance from the workplace) on unemployment. We begin with a brief summary of the economic literature on these issues. We then offer descriptive statistics to characterize the scope of residential segregation and spatial mismatch in the Paris region (Île-de-France) using 1999 census data and inter-city travel-time matrices for 2000. We conclude by estimating the effect of the local context (segregation and spatial mismatch ) on unemployment / employment transitions in the Paris region, using 1990-2002 Labor-Force Survey data. Our results show that unemployed persons in segregated districts have greater difficulty in finding new jobs.
The spatial mismatch hypothesis (SMH) argues that low-skilled minorities residing in US inner cities experience poor labour market outcomes because they are disconnected from suburban job opportunities. This assumption gave rise to an abundant empirical literature, which is rather supportive of the SMH. Surprisingly, it is only recently that theoretical models have emerged, which probably explains why the mechanisms of spatial mismatch have long remained unclear and not properly tested. This article presents relevant facts, reviews the theoretical models of spatial mismatch, confronts their predictions with available empirical results and indicates which mechanisms deserve further empirical tests.
We consider a search‐matching model in which black workers are discriminated against and the job arrival rates of all workers depend on social networks as well as distance to jobs. Location choices are mainly driven by racial preferences. There are multiple equilibria and we show that all workers are in general better off in the equilibrium where blacks are close to jobs. We also show that, in cities where black workers reside far away from jobs, the optimal policy is to impose higher quotas or employment subsidies than in cities where they live close to jobs.
What causes pockets of high unemployment within cities ? Economists point out at two alternative explanations : residential segregation as well as physical disconnection to jobs may have harmful labor-market effects. Our empirical work carried out on the Brussels metropolitan area supports the view that residential segregation exacerbates urban unemployment but does not enable us to assess the possible role of distance to jobs.
Blacks and whites have different incomes, decide where to locate in the city and which school to send their children to. We show that, despite the tuition fees imposed by whites and their remote location, some black pupils attend the private school. This market solution is shown not to be optimal because whites overprice education in order to limit black attendance at the private school. Three types of education policies are then considered: transportation subsidies, private-school vouchers and public-school spending. The efficiency of such policies depends on the fee-setting behavior of whites that strongly varies from one policy to another.
We model a South African city during Apartheid (in which both schooling and mobility are restricted on the basis of race) and after Apartheid (in which no restrictions are imposed). We first show that the inequality between blacks and whites decreases when apartheid laws are removed. Indeed, blacks are better off because of human capital externalities due to the possibility of mixing with white students, whereas whites are worse off due to negative human capital externalities and intensified land market competition. After Apartheid, we also show that reducing the commuting costs of black children always increases the utility of black families and may even increase that of whites.
This paper focuses on the role of social interactions in the location decision of workers and on the consequences of this decision on labor-market outcomes. More precisely, there are three categories of workers: whites, the ethnic minority workers who abide by the white group’s norms (referred to as ‘status-seekers’), and the ethnic minority workers who are willing to build or restore a group culture (referred to as ‘conformists’). Moreover, there are two main determinants of job acquisition: the inherited ‘history’ of workers (such as social networks or labor discrimination) and the physical distance between their residential neighborhood and the location of jobs. In this context, when locating in the city, workers face a trade-o¤ between commuting costs (which depend on their average employment spells) and their ethnic preferences. We show that there are multiple equilibria in which either whites reside close to the business district while conformists locate further away from jobs (Equilibrium 1) or conformists reside close to jobs while whites locate at the other end of the city (Equilibrium 2). In both cases, status-seekers live in between the two other communities. In this framework, we show that distance to jobs is crucial to the labor-market outcomes of ethnic minorities whereas it matters less for whites because of their strong inherited advantage in terms of history. Finally, even though we are not able to analytically rank the two equilibria, numerical simulations show that Equilibrium 2 leads to a higher surplus than Equilibrium 1 in the more realistic cases.
The barriers faced by Chinese rural–urban migrants to access social services, particularly education, in host cities could help explain why the majority of them choose to leave their children behind. We identified the causal impacts of school fees by instrumenting for it with unexpected shocks to the city’s public education spending. Our findings suggest that higher fees deter migrant workers from bringing their children with them, especially their daughters, reduce the number of children they bring, and increase educational remittances to rural areas for the children left behind. Increases in school fees mostly affect vulnerable migrant workers and could have stronger impacts during an economic crisis. These findings hold for different model specifications and robustness checks.
Other publications: books
with Alain Durand-Lasserve and Maÿlis Durand-Lasserve, Washington D.C.: The World Bank and Agence Française de Développement, 2015, 133 pages.
Urban and peri-urban land markets in rapidly expanding West African cities operate within and across different coexisting tenure regimes and involve complex procedures to obtain or make land available for housing. Because a structured framework lacks for the analysis of such systems, this book proposes a systemic approach and applies it to Bamako and its surrounding areas. The framework revolves around the description of land delivery channels: starting from the status of tenure when the land is first placed in circulation for residential use, it identifies the processes whereby tenure can be improved, the types of transactions that take place along the way, and interactions between land delivery channels.
Seventy-five percent of the world's poor live in rural areas and most are involved in agriculture. In the 21st century, agriculture remains fundamental to economic growth, poverty alleviation, and environmental sustainability. The World Bank's Agriculture and rural development publication series presents recent analyses of issues that affect the role of agriculture, including livestock, fisheries, and forestry, as a source of economic development, rural livelihoods, and environmental services. The series is intended for practical application, and hope that it will serve to inform public discussion, policy formulation, and development planning. Increased global demand for land because of higher and more volatile food prices, urbanization, and use of land for environmental services implies an increased need for well-designed land policies at the country level to ensure security of long-held rights, to facilitate land access, and to deal with externalities. Establishing the infrastructure necessary to proactively deal with these challenges can require large amounts of resources. Yet with land tenure deeply rooted in any country's history, a wide continuum of land rights, and vast differences in the level of socioeconomic development, the benefits to be expected and the challenges faced will vary across and even within countries, implying a need to adapt the nature and sequencing of reforms to country circumstances. Also, as reforms will take time to bear fruit and may be opposed by vested interests, there is a need to identify challenges and to reach consensus on how to address them in a way that allows objective monitoring of progress over time. Without this being done, the chances of making quick progress in addressing key land policy challenges are likely to be much reduced. The Land Governance Assessment Framework (LGAF) is intended as a first step to help countries deal with these issues. It is a diagnostic tool that is to be implemented at the local level in a collaborative fashion, that addresses the need for guidance to diagnose and benchmark land governance, and that can help countries prioritize reforms and monitor progress over time.
with Klaus Deininger, Derek Byerlee, Jonathan Lindsay, Andrew Norton and Mercedes Stickler, Washington D.C.: The World Bank, January 2011, 214 pages.
Interest in farmland is rising. And, given commodity price volatility, growing human and environmental pressures, and worries about food security, this interest will increase, especially in the developing world. One of the highest development priorities in the world must be to improve smallholder agricultural productivity, especially in Africa. Smallholder productivity is essential for reducing poverty and hunger, and more and better investment in agricultural technology, infrastructure, and market access for poor farmers is urgently needed. When done right, larger-scale farming systems can also have a place as one of many tools to promote sustainable agricultural and rural development, and can directly support smallholder productivity, for example, throughout grower programs. However, recent press and other reports about actual or proposed large farmland acquisition by big investors have raised serious concerns about the danger of neglecting local rights and other problems. They have also raised questions about the extent to which such transactions can provide long-term benefits to local populations and contribute to poverty reduction and sustainable development. Although these reports are worrying, the lack of reliable information has made it difficult to understand what has been actually happening. Against this backdrop, the World Bank, under the leadership of Managing Director Ngozi Okonjo-Iweala, along with other development partners, has highlighted the need for good empirical evidence to inform decision makers, especially in developing countries.
Other publications: book chapters
- Urbanisation et croissance dans les villes du Mali, with Sandrine Meslé-Somps, Gilles Spielvogel and Brian Blankespoor, in Brunet-Jailly J., Charmes J. and D. Konaté (eds): Le Mali contemporain, Editions IRD / Editions Tombouctou, 2014, 545-580.
- Spatial Mismatch, Poverty, and Vulnerable Populations, with Laurent Gobillon, in Fischer M. and Nijkamp P. (eds), Handbook of Regional Science, Springer, 2014, 93-107.
- Spatial Mismatch, with Laurent Gobillon, in Smith S., Elsinga M., Fox O’Mahony L., Seow Eng O., Wachter S. , Green R. (eds), International Encyclopedia of Housing and Home, Vol. 7. Oxford: Elsevier, 2012, 5-12.
- The Land Governance Framework. Methodology and Early Lessons from Country Pilots, with Klaus Deininger and Anthony Burns, in Deininger K., Augustinus C., Enemark S., Munro-Faure P. (eds), Innovations in Land Rights Recognition, Administration and Governance, The World Bank: Washington D.C., April 2010, 188-203.
- The Formalization of Urban Land Tenure in Developing Countries, with Alain Durand-Lasserve, in Lall S., Freire M., Yuen B., Helluin J.-J. (eds), Urban Land Markets: Improving Land Management for Successful Urbanization, Springer, October 2009, chapter 5, 101-132.
- Croissance périurbaine, ségrégation résidentielle et accès aux services publics, with Xavier Amet, Sylvie Charlot, Gaelle Contesti, Mohamed Hilal, Virginie Piguet, Bertrand Schmitt and Michael Visalli, in La Villepour Tous : un Enjeu pour les Services Publics, Partice Aubertel and François Ménard, eds., La Documentation Française, Paris, 2008, chapter 1, 37-49.
- Urban Unemployment in the Cape Metropolitan Area, with Sandrine Rospabé, in Poverty and Policy in Post-Apartheid South Africa, Haroon Bhorat and Ravi Kanbur, eds., Human Science Research Council: Pretoria, July 2006, chapter 7, 262-287.
- La mixité économique et sociale in Villes et Economie, Maurel, Perrot, Prager, Puig, Thisse, eds., La Documentation Française, Paris, 2004, chapter 5, 129-156.
- Les déterminants spatiaux du chômage en Ile-de-France, with Laurent Gobillon, in Ségrégation Urbaine et Intégration Sociale, Fitoussi, Laurent and Maurice, eds., CAE report N°45 (French council of economic advisors to the Prime Minister), La Documentation Française, Paris, February 2004, 171-187.
Other publications: blogs, papers in non-refereed journals, newspaper articles and columns
- Backyarding: from Cape Town to California, with Jan Brueckner and Claus Rabe, Orange County Register, November 14, 2019.
- Understanding Urban Land Markets in West Africa, with Alain Durand-Lasserve and Maylis Durand-Lasserve, African Can End Poverty, December 10, 2015 (also published in French on the World Bank's website and on the Agence Francaise de Developpement's website).
- How Roads Support Development, with Claudia Berg and Uwe Deichman, Let's Talk Development, December 08, 2015.
- The Global Land rush, with Rabah Arezki and Klaus Deininger, Finance & Development, March 2012, 46-49.
- From land demand to productive potential: Identification of countries where demand for land expansion may concentrate, with Klaus Deininger, IFPRI West & Central Africa Office Thematic Research Note 01, December 2011.
- La ségrégation résidentielle : un facteur de chômage, Regards Croisés sur l’Economie, 9, May 2011/1, 272-281.
- Did French enterprise zones fail poor areas? It is mainly about jobs, with Laurent Gobillon and Thierry Magnac, VoxEU.org, January 24, 2011.
- Le cycle des idées commence à Washington, Variances, 38, May 2010.
- Terres agricoles : OPA dans les PED, INRA Magazine, 11, December 2009.
- Discrimination ethnique et discrimination urbaine, with Laurent Gobillon and Thierry Magnac, Libération, May 6, 2009.
- Does finding work come down to who you are, or where you live?, with Laurent Gobillon and Thierry Magnac, VoxEU.org, March 17, 2007.
- Contre les ghettos : cibler les personnes et plus seulement les territoires, Telos - Agence Intellectuelle, February 11, 2006.
- Du bon usage des statistiques ethniques, Telos - Agence Intellectuelle, March 15, 2006.
- La mixité sociale: le point de vue des sciences économiques, Informations Sociales, 125, July 2005, 28-35.
- Chômage et ségrégation urbaine, with Laurent Gobillon, Lettre du CREST, November 2005.
- Ségrégation sociale et périurbanisation, with Jean Cavailhès, INRA Sciences Sociales, 1-2/03, November 2003, 4 pages.
- Ségrégation urbaine et accès à l'emploi, with Laurent Gobillon, Variances, May 2001.