Working Paper No. 788

Supply Function Equilibria: Step Functions and Continuous Representations

Published: January 29, 2009Pages: 48Keywords: Auctions; Supply Function Equilibria; Convergence of Step-Functions; Electricity MarketsJEL-codes: C62; D43; D44; L11; L13; L94
Published version

Supply Function Equilibria: Step Functions and Continuous Representations Pär Holmberg, David Newbery and Daniel Ralph

In most wholesale electricity markets generators must submit step-function offers of supply to a uniform price auction, and the market is cleared at the price of the most expensive offer needed to meet realised demand. Such markets can most elegantly be modelled as the pure-strategy, Nash Equilibrium of continuous supply functions, in which each supplier has a unique profit maximising choice of supply function given the choices of other suppliers. Critics argue that the discreteness and discontinuity of the required steps can rule out pure-strategy equilibria and may result in price instability. This paper argues that if prices must be selected from a finite set the resulting step function converges to the continuous supply function as the number of steps increases, reconciling the apparently very disparate approaches to modelling electricity markets.

Pär Holmberg


Ph: +46 8 665 4559
Mob: +46 72 511 6866

Sick of Inequality?

An Introduction to the Relationship between Inequality and Health

Sick of Inequality.jpg

In this book Andreas Bergh, Therese Nilsson, IFN and Lund University, and Daniel Waldenström, IFN and Paris School of Economics, France, review the latest research on the relationship between inequality and health. What does inequality mean for our health? Does increasing income inequality affect outcomes such as obesity, life expectancy and subjective well-being?


Seminars organized by IFN


To present ongoing research informal brown-bag seminars are held on Mondays at 11:30 am. This is an opportunity for IFN researchers to test ideas and results.

Academically oriented seminars are most of the time held on Wednesdays at 10 am. At these events researchers from IFN and other institutions present their research.

In addition, IFN organizes seminars open to the public. Topics for these are derived from the IFN research.

Research Institute of Industrial Economics, Grevgatan 34 - 2 fl, Box 55665, SE-102 15 Stockholm, Sweden | Phone: +46-(0)8-665 45 00 |