The welfare effects of third-degree price discrimination are known to be negative when demand functions are linear, marginal cost is constant and all markets are served. This paper shows that discrimination lowers welfare for a more general class of demand functions. Demand varies across markets...

This paper presents simple conditions for monopoly third-degree price discrimination to have negative or positive effects on aggregate consumer surplus.  Consumer surplus is often reduced by discrimination, for example when total welfare (consumer surplus and profits) falls.  Surplus increases...

The regulator of a natural monopoly that sets a two-part tariff and whose marginal cost is stochastic will generally want the price to vary less than marginal cost when the lump-sum charge in the tariff is fixed. A trade-off exists between efficient pricing and an optimal allocation of risk....

The paper shows how commodity taxes can provide insurance to consumers when the producer price is volatile. Specific and ad valorem taxes have differing roles. The optimal specific tax is positive when demand has some elasticity. The optimal ad valorem rate is zero when demand is unit-elastic,...

Sufficient conditions are developed for third-degree price discrimination by a monopolist serving all markets to reduce and raise social welfare.  Welfare falls if the demand function in the market whose price is higher with discrimination is at least as convex as that in the other market (at...

The paper assesses the welfare effects of different ways of allocating input price risk between a regulated utility, consumers and speculators in a futures market. A risk-averse utility setting a fixed retail price requires a price that exceeds expected marginal cost, unless an efficient futures...

The effects of demand shifts on output, price and profits in imperfectly competitive industries with no entry or exit are derived. Four types of demand shift are modelled: additive and multiplicative shifts of the demand and inverse demand functions. Necessary and sufficient conditions for...

Information technology, like the telephone, influences market access; this paper answers the question about a reverse effect, does market access affect information technology, in particular its adoption?  Using the introduction of the telephone in Bavaria, I demonstrate with a rank, order and...

This paper analyses and quantifies the effects of trade liberalisation and skill-biased technical change, both exogenous and trade-induced, on the skill premium and real wages of unskilled and skilled workers in the Mexican manufacturing sector, using industry- and firm-level data for 1984-1990...

In 1984, the world was shocked at the scale of a famine in Ethiopia that caused over half a million deaths, making it one of the worst in recent history.  The mortality impacts are clearly significant.  But what of the survivors?  This paper provides the first estimates the long-term impact...