At present, demand is almost completely unresponsive
to price in most power markets, since consumers usually face fixed
retail electricity prices, which do not reflect the time-varying marginal
wholesale cost of production. This is a source of inefficiency, in
particular in a deregulated power market, where utilities are exposed
to a competitive wholesale market. This work describes what is meant
by demand-side participation programs and the different ways they
can be implemented to promote demand responsiveness. The objective
is to highlight their effectiveness and their effects on consumers'
welfare. The theoretical advantages of dynamic pricing are discussed
together with the technological, cultural and regulatory barriers
that they face in practice. Benefits from such programs depend crucially
on the possibility to shift consumption across different time-periods.
Different empirical studies have provided estimates of this substitutability,
and here I present a survey of results and techniques. There is agreement
over the customer's ability to respond to price signals, but the extent
of such a response varies widely across users. This can raise equity
issues when implementing time-varying retail prices, that must be
assessed together with the expected benefits in terms of efficiency
brought by an increased demand responsiveness.