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Study Overview

Impact Evaluation of Rural Roads, Transport Costs, Women’s Access and Local Welfare in Guinea-Bissau
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This Impact Evaluation will help quantify the impact of better road infrastructure on local economic development with a special focus on women. It will also test whether investment in a complementary policy (feeder roads connected to the main trunk road) can help magnify the wider economic benefit of the road project. This impact evaluation will inform policymakers in Guinea-Bissau of whether the infrastructure is improving local economic development and leading to equitable access for all or if additional interventions are necessary to increase the impact of road rehabilitation for women.

Our theory of change is based on the premise that the immediate effect of the new road along with the rehabilitated feeder roads is the reduction of travel time and transportation costs between localities along Ingoré, Bigene, and Farim and to the Senegalese Border. As a result, the Rural Transport project is expected to reduce farmers’ trade and transportation costs and the population will have better access to markets. We expect this to generate an overall economic improvement for the population living close to the Engore-Farim road through greater mobility of people and goods. These analyses will be complemented by a structural model that relates road infrastructure to occupational choice, productivity, and welfare. This model will take into account the mobility of production factors such as labor as well as goods and allow to undertake counterfactual policy experiments with a focus on women working in the agriculture or trading sectors.

Registration Citation:

Bougna, T., and Nguimkeu, P., Sveta Milusheva, 2019. Impact Evaluation of Rural Roads, Transport Costs, Women’s Access and Local Welfare in Guinea-Bissau. Registry for International Development for Impact Evaluations (RIDIE). Available at 10.23846/ridie191

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Bougna, T. and Nguimkeu, P., 2019. Impact Evaluation of Rural Roads, Transport Costs, Women’s Access and Local Welfare in Guinea-Bissau. Registry for International Development for Impact Evaluations (RIDIE). Available at 10.23846/ridie191

Agriculture and Rural Development
Additional Keywords:
Impact evaluation, Feeder Road, Last mile, Infrastructure, Corridor, Gender, Structural Modelling, Guinea-Bissau
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Principal Investigator(s)

Name of First PI:
Theophile Bougna
The World Bank Group
Name of Second PI:
Pierre Nguimkeu
Georgia State University

Study Sponsor

The world Bank Group (DIME)
Study Sponsor Location:

Research Partner

Name of Partner Institution:
Ministry of Public Works, Guinea-Bissau
Type of Organization:
Government agency (eg., statistics office, Ministry of Health)

Intervention Overview


The proposed IE will focus on the rehabilitation and maintenance of about 110 km of unpaved trunk roads and connecting feeder roads in rural areas in the regions of Cacheu and Oio, between the towns of Ingoré and Farim in Northern Guinea-Bissau. These roads were selected based on a multi-criteria analysis from a socio-economic inventory and a technical assessment conducted in the project area. This inventory helped identify 425 km of unpaved roads, including three classified trunk roads (130 km) and a series of unclassified connecting feeder roads (295 km). The roads to be rehabilitated will mostly consist of spot improvements of existing roads by constructing or reconstructing culverts, drainage structures, and small bridges to prevent road closures during the rainy season (June-October) and improve all-weather passability. Rehabilitation works will also consist of construction or improvement of a small river ramp on the northern bank of the river Cacheu in Binta, a village served by one of the project roads and where a health center is located.

The proposed project is expected to directly benefit about 30,000 people in the targeted rural areas living within 2 km of the roads to be improved. These are mostly farmers engaged in subsistence agriculture who occasionally sell any agricultural surplus. Most households are also involved in livestock raising (cattle, sheep, and goats), and fishing in the Farim area is practiced by one-third of households. Some women in the project area are engaged in salt harvesting during the dry season. Other beneficiaries are households engaged in commercial farming, and particularly in the production of cashews and peanuts. The project impact area is one of the most important regions in the country for growing cashews, peanuts, cassava, and beans, which are the main cash crops for the country. There are respectively 229, 339, and 443 villages within 5, 10 and 15km of the project site.

Theory of Change:

Improving the above roads is expected to reduce travel time and transportation costs for users of the rehabilitated road in Cacheu and Oio regions of Guinea-Bissau. As a result, the population in the regions will have better access to markets and this will positively affect their social well-being, with better access to healthcare, education and other socio-economic infrastructures, especially for women and girls. Decreased travel time to an increased accessibility of social services and markets should, in turn, lead to better long-term outcomes in terms of health and consumption. Reaching a health facility faster could mean accessing care before health has deteriorated significantly, which should mean better vital signs and better long-term outcomes. Additionally, improved road conditions could lead to more diverse goods reaching markets, as well as lowered prices for goods or potentially the ability of individuals to travel to further markets that have lower prices. It also means the possibility for producers to access lower-priced inputs or additional inputs, as well as to access more markets where they can sell their goods. These could lead to changes in the consumption basket of households if they can purchase more goods with the same amount of money, and also purchase a more diverse array of goods.

Finally, the above-mentioned impacts are quite likely to be heterogeneous across firms, individual characteristics, and spatial locations. These heterogeneous effects will be explicitly modeled through a conceptual framework that relates road infrastructure to occupational choice, productivity, and welfare. Those living near the improved roads are expected to experience increased economic opportunity due to the increased traffic flow (in the case of those with businesses along the road) and increased mobility and connectivity.

Multiple Treatment Arms Evaluated?

Implementing Agency

Name of Organization:
The Ministry of Public work Guinea-bissau
Type of Organization:
Public Sector, e.g. Government Agency or Ministry

Program Funder

Name of Organization:
The World Bank Development Impact Evaluation Department
Type of Organization:
Foreign or Multilateral Aid Agency

Intervention Timing

Intervention or Program Started at time of Registration?
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Evaluation Method

Evaluation Method Overview

Primary (or First) Evaluation Method:
Difference in difference/fixed effects
Other (not Listed) Method:
Additional Evaluation Method (If Any):
Regression with controls
Other (not Listed) Method:

Method Details

Details of Evaluation Approach:

The first identification strategy relies on selecting the appropriate counterfactual rural roads based on the census of trunk and feeder roads that were planned to be rehabilitated but suspended or postponed for budget reason. This will help identify a number of roads that are targeted to be paved and are in very similar conditions to the Ingoré-Bigene-Farim road. For each of the planned outcome variables, we will define a set of observations which are treated and their counterfactual candidates. We then estimate the change over time in the treatment localities and households and subtract the change over time in control localities and households.

The second identification strategy we propose is a triple difference strategy. In the difference in difference strategy laid out above, we compare outcomes before-after (1st dimension) between settlements in the Ingoré-Bigene-Farim road to those outside the Ingoré-Bigene-Farim road (2nd dimension). In the triple difference strategy, we add a comparison between settlements along the rehabilitated road to those further away from the road. With the triple difference specification, the identifying assumption is that even if the Ingoré-Bigene-Farim road and the other similar road economic agents do not follow parallel trends, conditional on controlling for differences across roads, differences between economic agents close to the Ingoré-Bigene-Farim road and those further away from the Ingoré-Bigene-Farim road follow parallel trends. This approach departs from existing papers in the literature and is made possible by the high frequencies and the spatial granularity of our data.

Outcomes (Endpoints):

Primary outcome:

Household income and consumption

Women reduction in travel time to basic socio-economic infrastructure and markets (education, health, and markets)

Population increases/decreases at village level

Nighttime light intensity

Secondary outcome:

Traffic count


Travel time

Unit of Analysis:
Household and Settlements

The theory of change highlights the connection between road construction and our intermediate and final outcomes, with the most immediate being (i) the reduction of transportation and travel costs, and (ii) the expected increase in traffic flows, and (iii) the change in prices and market structure. These intermediate outcomes are expected to improve the wider economic benefits for economic agents living close to the road through (i) better service provision for those using the road, (ii) greater mobility and connectivity to better opportunities located elsewhere, and (iii) better connection to basic socio-economic infrastructure, especially for women who are very active in the project area.

Based on these hypotheses, this impact evaluation seeks to measure the impact of the road improvement on socio-economic indicator measures at both individual and village levels. Specifically, it will answer four primary research questions:

  • What is the impact of the rural road improvement and construction on local economic development: measured by change in nighttime lights, consumption, population?
  • What is the impact of the last mile connectivity (through feeder road improvement) on local economic development?
  • Are rural road investments alone sufficient to increase women’s access to markets and essential services?
      • What is the impact on the time necessary to reach basic socio-economic infrastructure such as hospital, market, schools?
      • What is the impact on agricultural production and profit for female producers?
      • What is the impact on female occupation choices (farm versus non-farm activities)?
Unit of Intervention or Assignment:
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Size of Treatment, Control, or Comparison Subsamples:
850 individuals each in treatment and control groups

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Outcomes Data

Data system: Customized households survey Existing ILAP and the ongoing LSMS Nighttime light from the National Oceanic and Atmospheric Administration
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Treatment Assignment Data

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Data Analysis

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Study Materials

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Registration Category

Registration Category:
Prospective, Category 1: Data for measuring impacts have not been collected

Completion Overview

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Preliminary Report:
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Data Availability

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Other Materials

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Study Stopped