B. Percentage absolute contribution of infrastructure to average log-productivity by key factors <!-- Start of picture text --> 100%<br>90%<br>80%<br>70%<br>60%<br>50%<br>40%<br>30%<br>20%<br>10%<br>0%<br><!-- End of picture text --> <!-- Start of picture text --> Use of generator or power infrastructures<br>Use of ICT<br><!-- End of picture text --> <!-- Start of picture text --> Provision of water<br>Transport services<br><!-- End of picture text --> <!-- Start of picture text --> Own transport infrastructures<br><!-- End of picture text --> <!-- Start of picture text --> Other<br><!-- End of picture text --> _Source_ : Author’s calculations with IC data.

_Note_ : Customs clearance includes: days to clear customs to export and import; shipment losses in customs; inspections in customs; wait for an import license. Provision of electricity includes: power outages; avg. duration of power outages; losses due to power outages, wait for an electricity supply; power fluctuations; avg. duration of power fluctuations; cost of electricity from the public grid; cost of electricity from private system. Use of power infrastructures includes: dummy for own generator; electricity from own generator; dummy for own power infrastructures (excl. generators). Provision of water includes: water outages; avg. duration of water outages; losses due to water outages, wait for a water supply; cost of water from the public grid; cost of water from private system. Use of water infrastructures includes: dummy for own water infrastructures; water from own well. Provision of phone includes: phone outages; avg. duration of phone outages; losses due to phone outages, wait for a phone connection. Use of ICT includes: dummy for e- mail; dummy for webpage. Transport services includes: sales lost due to transport delays; sales lost due to delivery delays; shipment losses; low quality supplies; transport delays. Own transport infrastructures include: dummy for own roads; dummy for own transportation for workers; products with own transport. Other: inventories, illegal payments to obtain public utilities.

Regarding _provision of water_ , the relative importance of this group of variables is lower when compared to the _provision of electricity_ ; nevertheless, there are some cases (such as Tanzania, Mali, and Kenya) where the contribution of this group of variables is very high, even compared to the provision of electricity. As with the provision of electricity, the use of alternative water infrastructure such as boreholes or wells has a positive impact on plants’ productivity—an effect that only appears to be significant when there is a negative effect of water provision, suggesting the existence of a replacement effect between the public provision of water and alternative supplies of water.

The poor quality of phone provision is negatively related to productivity in 14 countries; nevertheless, the quantitative contribution of this group of variables is, in general, lower than the impact of the electricity provision. Benin is an exception. The contribution to the average log productivity of telephone provision in this country is 40.8 percent—more than 20 times the contribution of electricity provision, which is only 2 percent. The use of IC technologies is positively related to productivity, but the use of these technologies was only significant in the productivity regressions of six countries: Malawi, Algeria, Tanzania, Kenya, Morocco, and Mauritius, with the largest impacts in Algeria (14.5 percent) and Mauritius (5.2 percent).

Problems with product transport are negatively related to productivity in all the cases, with the exception of Botswana, Swaziland, and Namibia, for which no variables for this group were significant in productivity regressions. The largest impacts of this subgroup of variables were seen in Senegal, 61