the highest overall effective tax rates tend to be in european countries and the lowest in australia new zealand and the americas if well targeted subsidies can weight incentives in favour of more environmentally sound activities and products address market failures and drive green innovation and investment governments spent an estimated usd billion on renewable energy subsidies worldwide in iea a mixed messages stopandgo policy making and retroactive changes can seriously weaken market signals however in the united states only gigawatt of new wind power capacity was installed in a fraction of the gigawatts installed in following the anticipated expiration of a tax credit on renewable electricity production at the end of iea a the credit was subsequently extended in late governments currently spend an estimated usd billion a year on environmentally harmful support for fossil fuels with an estimated usd billion spent by emerging and developing countries