Identifying and characterising price leadership in British supermarkets

Price leadership is a concept that lacks precision. We propose a deliberately narrow, falsifiable, definition then develop it, illustrate its feasibility and test it using the two leading British supermarket chains. We find both firms engaging in leading prices upward over a range of products, with the larger being initially more dominant but the smaller increasing leadership activity to take overall leadership over time. However, more price leadership events are price reductions than price increases, consistently led by the smaller firm. Nevertheless, the increases are of larger monetary amounts than the falls, so average basket price increases over time.     

A price leadership model for merger analysis

We provide a methodology to simulate the coordinated effects of a proposed merger using data commonly available to antitrust authorities. The model follows the price leadership structure in Miller, Sheu, and Weinberg (2021) in an environment with logit or nested logit demand. The model calibration leverages profit margin data to separately identify the extent of coordinated pricing from marginal costs. Using this framework, we demonstrate how mergers can shift incentive compatibility constraints and thereby lead to adverse competitive effects. The incentive compatibility constraints also affect the extent to which cost efficiencies and divestitures mitigate competitive harms.     

On the endogeneity of Cournot, Bertrand, and Stackelberg competition in oligopolies

In many industries, firms pre-order input and forward sell output prior to the actual production period. It is known that forward buying input induces a “Cournot-Stackelberg endogeneity” (both Cournot and Stackelberg outcomes may result in equilibrium) and forward selling output induces a convergence to the Bertrand solution. I analyze the generalized model where firms pre-order input and forward sell output. First, I consider oligopolists producing homogenous goods, generalize the Cournot-Stackelberg endogeneity to oligopoly, and show that it additionally includes Bertrand in the generalized model. This shows that the “mode of competition” between firms may be entirely endogenous. Second, I consider duopolies producing heterogenous goods. The set of equilibrium outcomes is characterized and shown not to contain the Bertrand solution anymore. Yet, forward sales increase welfare also in this case, notably even when goods are complements.     

Preemptive mergers under spatial competition

Mergers for market power generally benefit outsider firms more than participating firms. Hence, outsiders should welcome such mergers between their competitors but, frequently, this is not the case. Under spatial competition some outsiders gain more than the participating firms but others might benefit less. Thus, if the number of admissible mergers is limited, firms may decide to merge to preempt rival mergers. This paper studies the incentives for preemptive merger by firms engaged in spatial competition.     

Asymmetries in cost structures and incentives towards price competition

This paper provides some theoretical grounds to relate asymmetries in cost structures and incentives towards price competition. Typically low cost firms favor price competition whereas the reserve is true for high cost firms. Increased price competition will tend to diminish price-cost margins for all firms but the low cost firms may increase their total profits through an enlarged market share. This analysis depends on two relevant parameters: the way the overall market will react to increased price competition and interfirm cross elasticities. This is proved using comparative statics at the Nash equilibrium of an oligopolistic model.     

On the nature and significance of collusive price leadership

With the help of a simple analytical model we are able to analyze and to further clarify the conditions for collusive price leadership as they were originally devised by Jesse Markham. Within the confines of this model we show how collusion increases price-cost margins, but at the same time decreases concentration in the industry.     

A note on price cap regulation and competition

This paper examines the properties of a price-cap regulatory regime similar in design to a plan recently proposed by AGT Ltd. in hearings on Alternative Forms of Regulation before the Canadian Radio-television and Telecommunications Commission. The price-cap plan incorporates a number of novel features which include (i) quantity weights that evolve through time rather than remaining fixed; (ii) adjustments for productivity that incorporate yardstick competition; and (iii) allowing the weights to reflect the firm's market power or absence thereof in the presence of competition. Hence, should competitive circumstances permit, the regulatory regime allows for its own sunset.     

Spatial competition and price discrimination with capacity constraints

We characterize mixed-strategy equilibria when capacity-constrained suppliers can charge location-based prices to different customers. We establish an equilibrium with prices that weakly increase in the costs of supplying a customer. Despite prices above costs and excess capacities, each supplier exclusively serves its home market in equilibrium. Competition yields volatile market shares and an inefficient allocation of customers to firms. Even ex-post cross-supplies may restore efficiency only partly. We show that consumers may benefit from price discrimination whereas the firms make the same profits as with uniform pricing. We use our findings to discuss recent competition policy cases and provide hints for a more refined coordinated-effects analysis.     

Identifying airline price discrimination and the effect of competition

Empirical studies exploring the relationship between competition and price discrimination don’t generally consider the role of product differentiation or the asymmetric adoption of discrimination across firms. Using a customized empirical approach to examine the use of Saturday-night stayover discounts in the U.S. airline industry, I show that discounts are used more often when facing competitors that offer differentiated products but less often when competing with firms that don’t use discounts. Legacy carriers rarely use discounts when competing with Southwest or other low-cost carriers, but the presence of competing legacy carriers sometimes enhances the use of discounts.     

The competition effects of industry-wide vertical price fixing in bilateral oligopoly

This paper examines the competition and welfare effects of vertical price fixing through industry-wide resale price maintenance (RPM) arrangements, such as those benefiting from exemption from a general prohibition against RPM. A bilateral oligopoly framework is employed incorporating differentiation between manufacturer products and between retailer services. Transactions between the stages involve prices being determined through bargaining. We do not find RPM to be universally undesirable. However where retailer power is strong, the social effects of RPM are likely to be adverse, since the practice can assist in coordinating final price levels and prevent socially desirable countervailing power arising.     

The Ethiopian Commodity Exchange and spatial price dispersion

In this article, we study the impact of an institutional intervention on market efficiency in Ethiopia. More specifically, we analyze to what extent the Ethiopian Commodity Exchange (ECX) in combination with regional warehouses have contributed to a reduction in price spreads between regional markets. Our hypothesis is that warehouses connected to the ECX reduce the dispersion between export prices and local retail prices in different coffee growing areas, as well as the dispersion between export prices and local retail prices in different coffee growing areas. By doing so, the ECX has the potential to improve the market efficiency. To identify the causal effect, we combine retail price data with information on the gradual rollout of warehouses connected to the ECX from 2007 to 2012. Our results suggest that, when two markets both have access to an operating warehouse, the average price spread is 0.86–1.78 ETB lower than it is for markets where at least one part lacks warehouse access. This is a substantial reduction considering that the average price spread over the full period is 3.33 ETB. The main results are robust to various econometric specifications, and our analysis thus suggests that local warehouses connected to the ECX have indeed improved market efficiency.     

Simultaneous and sequential price competition in heterogeneous duopoly markets: experimental evidence

We investigate simultaneous and sequential price competition in duoply markets with differentiated products and random matching of symmetric firms. We find that second movers gain from the sequential structure in comparison to simultaneous-move markets whereas first movers do not. As predicted by the theory, there is a significant first-mover disadvantage in the sequential game. Finally, we report the results of control treatments varying the matching scheme and the mode of eliciting choices (strategy method vs. standard sequential play).     

An experiment on spatial competition with endogenous pricing

Hotelling's (1929) principle of minimum differentiation and the alternative prediction that firms will maximally differentiate from their rivals in order to relax price competition have not been explicitly tested so far. We report results from experimental spatial duopolies designed to address this issue. The levels of product differentiation observed are systematically lower than predicted in equilibrium under risk neutrality and compatible with risk aversion. The observed prices are consistent with collusion attempts. Our main findings are robust to variations in three experimental conditions: automated vs. human market sharing rule for ties, individual vs. collective decision making, and even vs. odd number of locations.     

Endogenous capacities and price competition: The role of demand uncertainty

We analyze the role of demand uncertainty in markets of fixed size, in which firms take long-run capacity decisions prior to competing in prices. We characterize the set of subgame perfect Nash equilibria under various assumptions regarding the nature and timing of demand uncertainty. In order to prove equilibrium existence, we identify a sufficient condition for the capacity choice game to be submodular. This condition resembles the standard downward-sloping marginal revenue condition used in Cournot games. A robust conclusion of the analysis is that equilibrium capacity choices are asymmetric, even when firms are ex-ante identical. Concerning the equivalence between the capacity-price game and the Cournot game, we find that with inelastic demands, the equilibria of the former belong to the equilibrium set of the latter. However, as compared to the Cournot game, the capacity-price game leads to lower prices and generates price dispersion.     

Stackelberg Independence*

The standard model of sequential capacity choices is the Stackelberg quantity leadership model with linear demand. I show that under the standard assumptions, leaders’ actions are informative about market conditions and independent of leaders’ beliefs about the arrivals of followers. However, this Stackelberg independence property relies on all standard assumptions’ being satisfied. It fails to hold whenever the demand function is non-linear, marginal cost is not constant, goods are differentiated, firms are non-identical, or there are any externalities. I show that small deviations from the linear demand assumption may make the leaders’ choices completely uninformative.     

Risks and spatial connectivity evidence from food price crisis in rural Indonesia

This paper examines the impact of the agricultural commodity price surge globally experienced in 2007/2008 and thereafter on income growth of agricultural producers and non-producers using recent panel data from Indonesia. First, during this period, producers experienced significantly higher earnings and total income growth than non-producers (narrowing their income gap). Second, the negative effect on non-producers’ real incomes was smaller in spatially well-connected areas, where, to mitigate the impact, private transfers (such as remittances) as well as employment incomes increased among non-producers. In contrast, government programs did not effectively cushion the income shock. Therefore, informal insurance was more effective than formal government-funded social protection programs to mitigate the crisis shock.     

Endogenous price commitment,sticky and leadership pricing: Evidence from the Italian petrol market

This article studies dynamic pricing strategies in the Italian gasoline market before and after the market leader unilaterally announced its commitment to adopt a sticky-pricing policy. Using daily Italian firm level prices and weekly average EU prices, we show that the effect of the new policy was twofold. First, it facilitated price alignment and coordination on price changes. After the policy change, the observed pricing pattern shifted from cost-based to sticky-leadership pricing. Second, using a dif-in-dif estimation and a synthetic control group, we show that the causal effect of the new policy was to significantly increase prices through sticky-leadership pricing. Our paper highlights the importance of price-commitment by a large firm in order to sustain (tacit) collusion.     

Game theoretical perspectives on dual-channel supply chain competition with price discounts and pricing schemes

This paper evaluates the impact of price discount contracts and pricing schemes on the dual-channel supply chain competition. Channel conflict occurs when the supplier enters the online direct channel. Traditional contracts normally require tedious administrational participation, full information of the cost structures, and other factors. The introduction of simple price discount contracts aims at providing easy implementation and effective coordination results. From supplier Stackelberg, retailer Stackelberg, and Nash game theoretic perspectives, we show that the scenarios with price discount contracts can outperform the non-contract scenarios. In addition, we show consistent pricing scheme can reduce the channel conflict by inducing more profit to the retailer. The leader in the games might, but is not guaranteed to, have advantages.