A novel method is proposed of estimating market concentration for the census case in which firms are grouped into size classes and all that is known about the firms in each category is their number and aggregate size. The formula arises as a way of applying an alternative expression for the...

Gibrat's law is augmented to produce a more general stochastic model of concentration consisting of growth, entry, and exit processes. Empirical facts on growth, entry, and exit reported elsewhere are employed to calibrate the model, which is then repeatedly simulated, generating concentration...

Seller concentration and its interactions on the performance of markets has occupied industrial organisation and competition economists for decades. While there has been much research on concentration in manufacturing markets, few studies have considered concentration in the services sector,...

Numerous methods have been proposed for calculating the Gini coefficient, the most widely used statistical measure of income inequality. The Milanovic (Bulletin of Economic Research, 46, 81-90, 1994) measure is simple, accurate and has attractive decomposition properties. However its use is...

Average revenue per user (ARPU) is commonly used by regulators and industry observers to compare the performance of mobile telephony markets. Under the new EU electronic communications regulatory framework, some national regulatory authorities (NRAs) have linked higher ARPU with 'significant...