# **_Baseline data, population and employment_**

The population and residential data shown in Figure 2 are based on the Population and Housing Census of 2010 (BBS 2011) at the union level. To best fit the model, we take households as the unit of observation and then re-scale the resulting spatial distribution of households by average household size to generate a spatial distribution of population. Following BBS (2011) we break the population down into those who report having completed secondary education or tertiary education, whom we define as skilled; the remainder of the working age population is defined as unskilled. We assume that the household head is the primary provider of labor, in which case 36 percent of households are classified as skilled. We also classify households into occupants of modern or traditional housing. This classification is based on building type, and the census reports four types of materials, namely, pucka, semi-pucka, kutcha and jhupri. We identify pucka housing as modern housing, which classifies 42 percent of the housing of the Greater Dhaka area as modern. Thus, we know, for each union, the number of households of each type (skilled/ unskilled) in housing of each type (modern/traditional).

Our data for the productive side of the economy are built up from employment data at the establishment location taken from the Economic Census 2013 (BBS 2014). The Economic Census reports 4-digit industry codes (BSIC 2009) and allows us to establish employment in manufacturing, non-tradable-services and tradable-services in each union. Tradable-services include financial services, professional and business services, information services, hospitals, universities, and air, railway and seawater transport related services. Additionally, the Population and Housing Census 2010 shows a significant proportion of households working in agriculture. We assume those who work in agriculture will work and live within the same union and are low-skilled, and we take the number of households classified as employed in agriculture from this data set.

# **_Transport Network_**

The transport network is mapped in 2011 using data from the Revised Strategic Transport Plan (DTCA 2015) and OpenStreetMap (2015). Travel times are estimated for both pedestrians and motorists. Most of the low-skilled workers in Dhaka walk to work and are therefore classified as pedestrians. We assume that these pedestrians can travel at 5 km/h, travelling to the nearest point on the road network and then following the roads through the city. Skilled workers are assumed to have access to motorized transport. We assign travel speeds for vehicles along different types of roads according to the number of lanes, with vehicles able to travel at 15km/hour on one lane roads, 20km/hour on two lane roads, and 60km/hour for four lane or wider roads. Network analysis is then conducted to find the shortest route between each pair of unions, taking into account the location of roads and the travel times down different types of roads. When we project Dhaka to 2035, we assume road and Mass Rapid Transit (MRT) investments as planned in the Revised Strategic Transport Plan (DTCA 2015), allowing lowskilled workers to use the MRT or travel on foot, whichever is quicker, and high-skilled workers to also have the option of driving. Congestion on roads increases proportionally with 9