The New Electricity Market of Singapore: Regulatory framework, market power and competition

This study examines whether the New Electricity Market of Singapore (NEMS) is functioning at a workable level of competition. The generation market of the NEMS appears highly concentrated by a four-firm concentration ratio or the Herfindahl–Hirschman Index. However, other measures of market power present that the NEMS is working at close to a competitive market. First, there seems to be a number of effective competitors in the market. Second, Supply Margin Assessment and Residual Supply Index support that the market is competitive though there are some possibilities in which the largest generator or a few large generators jointly could still have market power. Third, the Lerner Index of the NEMS shows that the generation market is fairly competitive and the Lerner Index adjusted with an industry level price elasticity of demand implies that there has not been much exercise of market power. Finally, vesting contracts—a contractual obligation of a specified quantity of electricity supply to the market—have appeared to be a strong and effective tool to mitigate market power in the NEMS. The vesting contracts are considered the force behind the lowering in the average Uniform Singapore Electricity Price and the Lerner Index in 2004.