**Table 9: Survey of selected papers on the development impact of rural roads in Africa**

|**Author**|**Level of**<br>**Analysis**|**Country/**<br>**Region**|**Indicator of**<br>**Development**|**Main Findings**|
|---|---|---|---|---|
|Nakamura et<br>al (2019)|Household|Ethiopia|Consumption|Rural road development increased household consumption by 16-28%, and<br>reduced poverty incidence by 14% in drought-affected areas.|
|Kebede<br>(2021)|Household|Ethiopia|Income|Road expansion resulted in a 13% increase in real agricultural income, on<br>average.|
|Ali et al<br>(2015b)|Household|Nigeria|Poverty/ Jobs|Reducing transport costs increases local GDP /wealth and lowers households’<br>probability of being poor and agriculturally employed.|
|Gachassin et<br>al (2015) *+|Household|Cameroon|Earnings|Better road access increases the number of economic activities within<br>households that are most isolated.|
|Dorosh et al<br>(2012) *+|Country|Sub-Saharan<br>Africa|Agricultural<br>Production|A 10% (1%) decrease in travel time from crop production areas to small (large)<br>towns increasing production by 23% (3%) in the long run.|
|Aggarwal et<br>al (2018)|Village|Tanzania|Agricultural<br>Production|A village in the 90<sup>th</sup>percentile of the travel-cost adjusted price distribution faces<br>input and output prices 40-55% less favorable than a village at the 10<sup>th</sup><br>percentile.|
|Minten et al.<br>(2013)|Household|Ethiopia|Agricultural<br>Production|Increasing transportation costs over a 35 km distance, leads to a 50% increase of<br>the price of chemical fertilizer and to a 75% reduction in its use.|
|Minten and<br>Kyle (1999) *|Trader|Democratic<br>Republic of<br>Congo|Food Prices|Transportation costs explain most of the food price differential between<br>producing regions, with road quality an important driver of transportation costs.|
|Casaburi et al<br>(2013)|District|Sierra Leone|Food Prices|Improved rural road quality reduced prices for two main domestically produced<br>staple crops (rice and cassava) particularly in more remote areas.|
|Lall et al.<br>(2009)|Household|Malawi|Trade|Both infrastructure quality, and market structure of the trucking industry, are<br>important contributors to regional differences in transport costs.|
|Blimpo et al<br>(2013) *|Local<br>admin.<br>Unit|Benin,<br>Ghana, Mali,<br>Senegal|Food<br>Security|There is a strong correlation between food security and availability of road<br>infrastructures.|
|Gachassin<br>(2013) *|Household|Tanzania|Migration|Road quality improvements decrease the probability of migration by 7%, and<br>even more so in well-connected communities.|
|Jedwab and<br>Storeygard<br>(2022) *+|Location|Sub-Saharan<br>Africa|Migration|Greater market access increases city population on average; particularly for<br>smaller and more isolated cities and for domestic markets.|
|Storeygard<br>(2016) *|Pixel|Sub-Saharan<br>Africa|Income|An oil price hike induces the income of cities near that port to increase by 7%<br>relative to otherwise identical cities 500 km farther away.|

Source: Compiled by the authors.

Note: Findings column is based on the main finding of the paper. An asterisk identifies peer-reviewed papers. Plus identifies papers following the instrumental variable approach.

Sub-Saharan Africa is the region with the highest degree of isolation, scoring just 30 percent on the Rural Access Index, for the percentage of the population living within two kilometers of an all-season road. Nevertheless, South Asia and Latin America, with Rural Access Index scores of 58 29