ARBITRAGE BOUNDS FOR PRICES OF WEIGHTED VARIANCE SWAPS

We develop a theory of robust pricing and hedging of a weighted variance swap given market prices for a finite number of co‐maturing put options. We assume the put option prices do not admit arbitrage and deduce no‐arbitrage bounds on the weighted variance swap along with super‐ and sub‐replicating strategies that enforce them. We find that market quotes for variance swaps are surprisingly close to the model‐free lower bounds we determine. We solve the problem by transforming it into an analogous question for a European option with a convex payoff. The lower bound becomes a problem in semi‐infinite linear programming which we solve in detail. The upper bound is explicit. We work in a model‐independent and probability‐free setup. In particular, we use and extend Föllmer's pathwise stochastic calculus. Appropriate notions of arbitrage and admissibility are introduced. This allows us to establish the usual hedging relation between the variance swap and the “log contract” and similar connections for weighted variance swaps. Our results take the form of a FTAP: we show that the absence of (weak) arbitrage is equivalent to the existence of a classical model which reproduces the observed prices via risk‐neutral expectations of discounted payoffs.     

Evidence on the impact of minimum wage laws in an informal sector: Domestic workers in South Africa

What happens when a previously uncovered labor market is regulated? We exploit the introduction of a minimum wage in South Africa and variation in the intensity of this law to identify increases in wages for domestic workers and no statistically significant effects on employment on the intensive or extensive margins. These large, partial responses to the law are somewhat surprising, given the lack of monitoring and enforcement in this informal sector. We interpret these changes as evidence that strong external sanctions are not necessary for new labor legislation to have a significant impact on informal sectors of developing countries, at least in the short-run.     

The micro elasticity of substitution and non‐neutral technology

This article provides evidence on the micro capital‐labor elasticity of substitution and the bias of technology. Using data on US manufacturing plants, I find several facts inconsistent with a Cobb‐Douglas production function, including large, persistent variation in capital shares. I then estimate the elasticity using variation in local wages, and several instruments for them, for identification. Estimates of the substitution elasticity using all plants range between 0.3 and 0.5, with similar estimates across industries. I use these elasticity estimates to measure labor augmenting productivity, and find that labor augmenting productivity is highly persistent, and correlated with exports, size, and growth.     

The exchange rate regime in Asia: From crisis to crisis

Prior to the Asian financial crisis, most Asian exchange rates were de facto pegged to the US Dollar. During the crisis, many economies experienced a brief period of extreme flexibility. A ‘fear of floating’ gave reduced flexibility when the crisis subsided, but flexibility after the crisis was greater than that seen prior to the crisis. Contrary to the idea of a durable Bretton Woods II arrangement, Asia then went on to slowly raise flexibility and reduce the role for the US dollar. When the period from April 2008 to December 2009 is compared against periods of high inflexibility, from January 1991 to November 1991 and October 1995 to March 1997, the increase in flexibility is economically and statistically significant. This paper proposes a new measure of dollar pegging, the “Bretton Woods II Score”. We find that Asia has been slowly moving away from a Bretton Woods II arrangement.     

Estimating the Short Run Effects of South Africa's Employment Tax Incentive on Youth Employment Probabilities using A Difference‐in‐Differences Approach

South Africa's Employment Tax Incentive (ETI) came into effect on the 1st of January 2014, with the objective of reducing the substantial national youth unemployment rate. Under the ETI, firms are eligible to claim a deduction from their taxes due, for the portion of their wage bill that is paid to certain groups of youth employees. We utilise several waves of nationally representative data and implement a difference‐in‐differences methodology at the individual level, in order to identify the effects of the ETI on youth employment probabilities in the short run. Our primary finding is that the ETI did not have any statistically significant and positive effects on youth employment probabilities. The point estimate from our preferred regression is ?0.005 and the 95% confidence interval is from ?0.017 to 0.006. We also find no evidence that the ETI has resulted in an increase in the level of churning in the labour market for youth. Thus, any decrease in tax revenues that arise from the ETI are effectively accruing to firms which, collectively, would have employed as many youth even in the absence of the ETI.     

Analysing the risks of adopting circular economy initiatives in manufacturing supply chains

The concept of circular economy (CE) has proven its worth due to the scarcity of natural resources and huge amounts of wastage which impacts the environment. Thus, the adoption of the CE concept in the supply chain becomes critical. However, due to the complex nature of processes/activities in the circular supply chain (CSC), managing risk has become a priority to avoid disruption. In current literature, no discussion has been conducted on how to analyse the risks in the context of CSC. Therefore, to fill this literature gap, this study concentrates on identifying and analysing the risks to promote effective circular initiatives in supply chains in the context of the manufacturing industry, thus minimising the negative environmental impact. A total of 31 risks were identified through an extensive literature review and discussions with experts. A grey-based decision-making trial and evaluation laboratory (DEMATEL) method is applied by incorporating the experts' knowledge to compute prominence and cause/effect scores to develop an interrelationship map. Finally, a vulnerability matrix for risk categories is developed using the average of prominence and cause/effect scores of risks. The results show that transparent process is the most prominent risk and branding is the least significant risk. By using the average prominence and cause/effect score, a risk category, namely, financial risk, is identified as most vulnerable to CSC. These findings will help industry managers not only to prepare business strategies in the adoption of CE initiatives in supply chains by eliminating risks but also in minimising negative environmental impact.     

Labour Market Dynamics in South Africa at the Onset of the COVID-19 Pandemic

This paper conducts an analysis of labour market dynamics in South Africa during the initial period of lockdown, from the end of March to the end of April 2020, using the first wave of the NIDS-CRAM (2020) survey. Within our sample of over 6,000 adults aged 18 to 59, we found that there was a very large decrease in employment. The fraction of the sample that was conventionally classified as employed decreased from 57% in February to 48% in April. If we further exclude temporarily absent workers, which we term “furloughed” employees, this fraction decreases further to 38%. Thus, about one out of every three employed people in our sample either lost their job or did not work and received no wages during April. This has extremely large implications for poverty and welfare. We further analyse the labour market by comparing across demographic groups as defined by race, by gender, by age groups, by geographic areas and by education levels. The over-arching finding from this analysis is that the job losses were not uniformly distributed amongst the different groups. In particular, groups who have always been more vulnerable – such as women, African/Blacks, youth and less educated groups – have been disproportionately negatively affected.     

Estimating the Size and Impact of Affirmative Action in Undergraduate Admissions at the University of Cape Town

In this paper, we estimate the extent and targeting of affirmative action at the University of Cape Town (UCT), a large public university in South Africa. To do this we use admissions data from the UCT, as well as South African population census data and administrative enrolment and graduation data from the South African Department of Higher Education. We find that affirmative action does have a significant effect on the racial distribution of who is made an offer by the university. We also find that affirmative action is well targeted, with those who we estimate to be beneficiaries being of much lower socioeconomic status than those who we estimate are displaced by affirmative action. Beneficiaries of affirmative action have low graduation rates on average, with those beneficiaries who attend UCT being less likely to graduate than those beneficiaries who enrol at other public universities.     

Contextual factors that foster or inhibit para‐teacher professional development: the case of an Indian,non‐governmental organization

The appointment of para‐professionals to overcome skill shortages and/or make efficient use of expensive resources is well established in both developing and developed countries. The present research concerns para‐teachers in India. The literature on para‐teachers is dominated by training for special needs settings, largely in developed societies. Little has been published about para‐teachers working in developing countries with children without disabilities, despite this being a common occurrence. The present research investigates how contextual factors influence the design and implementation of professional support for para‐teachers. The research participants were 12 para‐teachers and five management and administrative staff. Contextual factors included characteristics of para‐teachers, classrooms and students from under‐resourced settings; and the practices and policies found in a non‐school educational setting, here a non‐governmental organization. The study indicates that each factor has potentially enhancing and hindering effects which need to be taken into consideration when designing and implementing professional development work.