Schooling is typically found to be highly correlated with individual earnings in African countries.  However, African firm or sector level studies have failed to identify a similarly strong effect for average worker schooling levels on productivity.  This has been interpreted as evidence that...

In this paper we review some recent work on limit results on realised power variation, that is sums of powers of absolute increments of various semimartingales. A special case of this analysis is realised variance and its probability limit, quadratic variation. Such quantities often appear in...

This paper explores the extent and nature of gender differences, by age, in household health expenditure allocation.  Using South African data, we adopt a hurdle methodology, constructing a sequence of decision stages (reporting sickness, consulting medical practitioner, incurring positive...

In this paper we analyse the relative importance of individual ability and labour market institutions, including public sector wage setting and trade unions, in determining earnings differences across different types of employment. To do this we use the KwaZulu-Natal Income Dynamics Study data...

Commentators claim that a shortage of skills in South Africa is constraining output and that a rise in skill supply would benefit less skilled occupations. This assumes or implies skilled and unskilled labour are complements. Hicks Elasticities of Complementarity and elasticities of factor price...

What drives migration and remittance behaviour in South Africa, and what are the implications for public policy? This paper evaluates existing empirical evidence, posits a simple theoretical model and undertakes a fresh evaluation using longitudinal data spanning 1993 to 2004 from KwaZula-Natal...

To forecast at several, say h, periods into the future, a modeller faces two techniques: iterating one-step ahead forecasts (the IMS technique) or directly modelling the relation between observations separated by an h-period interval and using it for forecasting (DMS forecasting). It is known...

In this paper we provide an asymptotic distribution theory for some non-parametric tests of the hypothesis that asset prices have continuous sample paths. We study the behaviour of the tests using simulated data and see that certain versions of the tests have good finite sample behaviour. We...

Here we assume that the logarithmic asset price is given by a semimartingale. Jacod (2006) has derived an infeasible central limit theorem for the realised variance in such a general framework. However, here we focus on constructing a feasible limit theorem. We propose a new estimator for the...

This paper analyses multivariate high frequency financial data using realised covariation. We provide a new asymptotic distribution theory for standard methods such as regression, correlation analysis and covariance. It will be based on a fixed interval of time (e.g. a day or week), allowing the...