In particular, variability and volatility of revenues for peak power plants, the load factor risk and peak prices may remain a concern. In this respect, IEA countries face different situations. Most states have already developed or improved energy markets and will continue to do so. While some regions face urgent generation adequacy constraints (the United Kingdom and Japan, for instance), most of other countries have enough excess-capacity, as a result of sluggish demand growth. In the latter case, reforming electricity market design is not seen as a pressing concern.