point to a very large number, on the order of magnitude of US$1 trillion annually.<sup>3</sup> Furthermore, these lessons are also likely to be applicable to non-transport infrastructure investments such as electrification or Internet connectivity programs.

We study a rural roads improvement project in Vietnam using mixed methods analysis to assess whether the impacts of road rehabilitation differed across genders, and to better understand the underlying mechanisms. Specifically, we first measure causal impacts of road improvement on average and by gender applying a difference-in-differences framework to a combination of survey and administrative data. We then complement these results with qualitative data collection that aims to shed light on the mechanisms that may prevent either gender from fully benefiting from infrastructure improvements economically and socially.

The remainder of the paper is structured as follows: we describe the project interventions in more detail in Section 2. Sections 3 and 4 discuss the data and methodology, respectively. Results are discussed in Section 5. Section 6 provides conclusions.

# 2. Intervention Description

We analyzed rural road improvements carried out under a large-scale project, the Third Rural Transport Project (RTP3), in Vietnam<sup>4</sup> ( <mark>World Bank, 2015) t</mark> hat was implemented between 2008 and 2015 (Table A.1). Under the project, approximately 3,100 km of rural roads were rehabilitated, and maintenance activities were implemented on over 19,000 km of rural roads spread across 33 provinces in Northern and Central Vietnam (Figure A.1).

The interventions under RTP3 cover activities classified as either rehabilitation or maintenance under the program and in the administrative data that we use for the analysis. Road maintenance is important since it receives a low level of investment despite being critical to sustaining road quality in the face of not only traffic impacts, but also severe weather.<sup>5</sup> Flooding, landslides, and slope and coastal erosion during the rainy season are common occurrences in many rural areas. Maintenance, particularly clearing drainage systems like culverts and side drains, can both reduce the chances of flooding of roads and the consequent deterioration in road quality after flooding. Maintenance was further categorized into two types of interventions based on the type and the periodicity of the activities, and who implements the activity. Overall, the project activities are classified into three types of interventions in the administrative data:

> 3 The estimates range from US$900 billion in studies by the Institute for Transportation and Development Policy (ITDP) and EMBARQ (Sakamoto et al. 2010; Mahendra et al. 2013), between US$1.4 trillion and US$2.1 trillion in a World Resources Institute (WRI) study (Lefevre et al. 2014), and US$2.6 trillion in a study by the International Energy Agency (IEA) (Dulac 2013).

> 4 The World Bank Group was one of the donors for this project.

> 5 This is acknowledged in the development objective of the project, which is to “improve year-round access to markets, economic opportunities and social services for rural populations.”

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