Learning about Risk and Return: A Simple Model of Bubbles and Crashes

This paper demonstrates that an asset pricing model with least-squares learning can lead to bubbles and crashes as endogenous responses to the fundamentals driving asset prices. When agents are risk-averse they need to make forecasts of the conditional variance of a stock’s return. Recursive updating of both the conditional variance and the expected return implies several mechanisms through which learning impacts stock prices. Extended periods of excess volatility, bubbles and crashes arise with a frequency that depends on the extent to which past data is discounted. A central role is played by changes over time in agents’ estimates of risk.

The Living Wage: Reducing inequality in the UK?

The revival of support for a living wage has reopened a long-run debate over the extent to which active regulation of labour markets may be necessary to attain desired outcomes. Market failure is suggested to result in lower wages and remuneration for low skilled workers than might otherwise be expected from models of perfect competition. This paper examines the theoretical underpinning of living wage campaigns and demonstrates that once we move away from idealised models of perfect competition to one where employers retain power over the bargaining process, such as monopsony, it is readily understandable that low wages may be endemic in low skilled employment contracts. The paper then examines evidence, derived from the UK Quarterly Labour Force Survey, for the extent to which a living wage will address low pay within the labour force. We highlight the greater incidence of low pay within the private sector and then focus upon the public sector where the Living Wage demand has had most impact. We examine the extent to which addressing low pay within the public sector increases costs. We further highlight the evidence that a predominance of low pay exists among public sector young and women workers (and in particular lone parent women workers) but not, perhaps surprisingly, among workers from ethnic minority backgrounds. The paper then builds upon the results from the Quarterly Labour Force Survey with analysis of the British Household Panel Survey in order to examine the impact the introduction of a living wage, within the public sector, would have in reducing household inequality. The paper concludes that a living wage is indeed an appropriate regulatory response to market failure for low skilled workers and can act to reduce age and gender pay inequality, and reduce household income inequality among in-work households below average earnings.

A Simple Characterization of Dynamic Completeness in Continuous Time

This paper investigates dynamic completeness of financial markets in which the underlying risk process is a multi-dimensional Brownian motion and the risky securities dividends geometric Brownian motions. A sufficient condition, that the instantaneous dispersion matrix of the relative dividends is non-degenerate, was established recently in the literature for single-commodity, pure-exchange economies with many heterogenous agents, under the assumption that the intermediate flows of all dividends, utilities, and endowments are analytic functions. For the current setting, a different mathematical argument in which analyticity is not needed shows that a slightly weaker condition suffices for general pricing kernels. That is, dynamic completeness obtains irrespectively of preferences, endowments, and other structural elements (such as whether or not the budget constraints include only pure exchange, whether or not the time horizon is finite with lump-sum dividends available on the terminal date, etc.)