using 6‐digit HS product codes (1992 revision). Using Atlas trade data requires matching HS 1992 to ISIC revision 4, using the relevant correspondence table provided on the World Trade Integrated Trade Solutions website.<sup>6</sup> This table matches the 6‐digit HS (revision 1992) codes to ISIC (revision 2) 4‐digit codes. We then move from revision 2 to revision 4 of the ISIC.

The second source of data is the population census data. The 2000 population census data (undertaken 3 years before the 2003 NIC) was obtained from IPUMS, which gives a number of other characteristics of each district, including measures of the overall size of the potential market locally (proxied by the total number of individuals in wage and self‐employment in each district) and measures of human capital in each district. The data also includes the size of each district, which we use to compute employment density, an urbanization economy that may contribute to local employment growth. We can also use the IPUMS population census data to obtain spatial information on the distance of the centroid of each district from both Kumasi and Accra, which we believe are reasonable measures of transport costs to large markets and (for Accra) export markets. This data is created using the GIS information contained in the IPUMS release of the 2000 population census.

We also have district‐level population census data for 1984 and 1970. These are based on the census microdata but are not publicly available. They were obtained from Lasse Møller‐Jensen at the University of Copenhagen and were used in Møller‐Jensen and Knudsen (2008).

# 4 Descriptive Analysis

Before investigating the determinants of local growth in Ghana we describe employment growth in Ghana, the distribution of the localization and urbanization measures that we use in our growth regression analysis and the population and trade data.

## 4.1 Ghanaian firm census data

### **Firm level data**

Table 1 shows the employment and firm numbers and shares of each of the 10 regions in Ghana in the 2003 and 2013 censuses. Greater Accra and Ashanti, which contains the second city of Kumasi, dominated manufacturing employment in 2003, accounting for 58%. The 2000 population census indicates that these two regions had a population share of only 34%, so that employment is heavily concentrated in these two regions, relative to their population shares. By 2014 Greater Accra had increased its share of total employment to 43%, whilst Kumasi’s share shrank by one third. The shares of total employment in the five northern/central/eastern regions increased whilst southern regions’ shares generally declined, other than Greater Accra. These patterns are broadly repeated when looking at the firm numbers and shares of firms. Kumasi’s share of firms again declined whilst the smaller regions increased. Greater Accra’s share stayed constant, suggesting that Greater Accra had a much larger average firm size.

The increasing concentration of employment in the firm censuses in greater Accra shown in Table 1 is important, since agglomeration economies may be a part of the explanation for this pattern. This is not the pattern shown in Lall et al (2009), who used the 1987 and 2003 censuses to show deconcentration away from Accra and Kumasi. Above we noted that the deconcentration result is likely to be due to comparability issues in these two firm censuses, which we have discussed in Kerr and McDougall (2019). We think the 2003 and 2014 firm censuses are more comparable, and in this

> 6 Available at https://wits.worldbank.org/product_concordance.html.

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