Prof. W.H. Boshoff
The declaration of a state of national disaster in South Africa, due to the Covid-19 pandemic, was followed by excessive-pricing regulations pertaining to certain consumer and medical products and services. The regulations and their application suggest an intertemporal benchmark to judge excessive pricing, deviating from previous practice. Intertemporal comparisons assume a structural shift during Covid-19 that changes competitive conditions, related to changes in consumer behaviour. Such comparisons must also account for demand and cost changes. While the Covid-19 regulations allow for cost-based price increases, demand-based increases are not explicitly accounted for, suggesting that the regulations are framed more generally as price-gouging regulations. The differences between price-gouging and excessive pricing benchmarks depends on the type of disaster-period demand shock. They are similar following a transitory demand spike, provided sufficient time is allowed for dynamic price behaviour, but differ markedly when demand is elevated for the duration of the disaster period. Applying simple cost-based comparisons in recently concluded cases against smaller retailers are consistent with excessive pricing, given the presence of a demand spike. To the extent that these involve persistently-higher demand, cases against wholesalers and larger retailers will be more complicated, as such demand must be reflected in competitive prices.

Paul W.J. de Bijl and Helanya Fourie
This paper explores the relationship between local public ownership and the sustainability mission of companies in the energy transition. Public ownership may matter due to “contractual incompleteness” where legislation and regulation fall short in dealing with market failures or addressing public interests. Ownership provides a measure of influence and control over the mission and strategy of a company, which is important in light of the unanticipated consequences of the energy transition. The role of municipal ownership is underlined by the growing popularity of district heating and cooling systems and the impact of the energy transition on the urban environment.

Willem Boshoff & Rossouw van Jaarsveld
Collusion is often a recurrent phenomenon, with cartel periods interspersed by periods of greater competition. In developing countries in particular, industries with a history of legal collusion are often characterized by recurrent collusion. Canonical models implicitly treat collusion as recurrent by modelling collusion as a state dependent outcome, often based on an unobserved demand state. Yet empirical studies have paid less attention to recurrent collusion. This paper proposes a Markov regime-switching (RS) model to detect recurrent periods of collusive damages and to estimate price overcharge in these cases. An empirical model of recurrent collusion must satisfy three properties. Firstly, it should account for dierent datagenerating processes during collusive and non-collusive episodes. Secondly, it should be able to detect the dates and duration of collusive and non-collusive episodes. Thirdly, it should account for  exible transitions between collusive and non-collusive episodes. We argue that the RS model meets these requirements. We demonstrate these features in an application to the South African cement market, which, similar to cement markets in a number of other countries, have experienced recurrent collusion. Our results suggest that the exclusion of non-collusive periods { including price wars { yield higher overcharge estimates than conventional approaches. In competition policy, the RS model can act as a screening tool, to identify recurrent collusive behaviour. Courts may also nd the RS model useful when estimating collusive damages, especially in private litigation, where the court must also determine the period of liability.