Building productive capacity through increasing revenue  Between 2003-2009 the annual growth rate of mobile cellular subscriptions in Tanzania was 44.21%, higher than the average in Africa (Ondiege, 2010). Estimations suggest around 18bn Tsh [1] will be collected a month through the SIM card tax model (Rweyemamu, 2013). In 2012, Tanzania’s total GDP was calculated at ~45tr Tsh [2] - the tax could therefore provide almost 0.5% of GDP in taxes. Such a boost in government taxation will enable projects such as improving rural infrastructure (including potentially mobile phone coverage!) or help reduce the deficit. That one tax can raise so much shows the potential of this kind of taxation.  [1] Equates to ~11.2mn USD (January 2013).  [2] Calculated based on World Bank Data (2013) and exchange rate as per January 2013.