Key Points:An unprecedented infrastructure investment boom occurred in the Gulf Cooperation Council (GCC) in the first part of the 21st century. Strong public capital spending supported by high energy prices provided governments with an opportunity to accelerate economic diversification and infrastructure investment, lifting economic growth and per capita incomes. The 2014 collapse in oil prices created an added impetus for a transition to a more sustainable growth model less dependent on volatile energy markets. Here we make the case for a greater focus on energy productive investment to drive this transition.Although evidence suggests that some GCC countries are beginning the transition to a more energy productive investment paradigm, in other countries capital investment is not lifting energy productivity. Particular progress has been made in recent years in the UAE, Saudi Arabia and Kuwait. Qatar has experienced the strongest growth in infrastructure investment (in percentage terms), but in recent years its energy productivity has declined significantly. In Bahrain, a decline in capital investment has also been accompanied by stagnation in its once-improving energy productivity. Oman remains strongly on a low energy productivity growth path.Given that GCC governments face a constrained fiscal environment and low domestic energy prices remain for consumers, we suggest that policymakers consider a market-based 'negabarrel' program to stimulate energy productivity investment. Such a program would commoditize the value of avoided energy consumption and could provide social benefits in terms of extra energy available to export and avoided capital expenditure on new electricity generation capacity. This value is currently not available to the private sector and low prices provide weak incentives for the private sector to invest in energy productivity. A 'negabarrel' program on the scale of around USD 100 billion across the GCC implemented over 10 years could incentivize private sector investment, generate around 800,000 to 1.2 million new jobs and increase government revenue, if a robust energy service company (ESCO) market can be established. Implementation programs, such as super ESCOs, need careful planning, but can deliver substantial economic benefits and employment opportunities for GCC citizens in the area of energy auditing and management.Even in a low oil price environment there are significant opportunities to improve energy productivity in a cost-effective way across the GCC economies and the potential national benefits should make this an investment priority. Within Saudi Arabia improving energy productivity can sit well within the 2030 vision direction. Recent increases in end-user energy prices across the GCC, have shifted the balance of benefits more towards the energy user but joint public-private sector actions will still be required to catalyze the required actionsOther financing options to support the transition to higher energy productivity include incorporating energy productivity criteria into existing public capital spending; establishing a new public financing vehicle specifically for energy productivity investment; and issuing energy productivity 'green' bonds, including Green Sukuk.As for all investments, the risks of energy productivity investment are real, but so too are the benefits for citizens, businesses and governments.