Emissions abatement falls first on those polluters that handle it in the most cost-efficient manner, which provides incentives to reduce pollution and emissions and to invest in environmentally friendly technologies. Market instruments are less information-intense in that they require only regulators to set the price (in the case of a tax) or the quantity (in the case of an ETS) of the relevant instrument, but this also gives them less control over the actual environmental outcome. Energy subsidies - especially on petroleum products and electricity - are prevalent in Asia, which accounted for about one third of global energy subsidies in 2013.