Evolving Market Efficiency with an Application to Some Bulgarian Shares

With new technically advanced methods and computers at our disposal, the efficient market hypothesis is once again being debated. At the same time, we are witnessing an unprecedented growth in both existing and new financial markets. These new markets are often in economies which have just recently embraced free market economics; we term these stock markets infant markets. Such stock markets are obviously not efficient in allocating the supply of savings to productive capital. We do not test whether or not these infant markets are informationally efficient, but instead examine whether and how they are becoming more efficient. We propose modelling the excess returns of individual securities using a multi-factor model with time-varying coefficients and generalised auto-regressive conditional heteroskedastic (GARCH) errors. If the markets are becoming more informationally efficient or the agents are learning, we would expect this to manifest itself as the time-varying coefficients becoming more stable as time increases. We test our model using data on four Bulgarian shares. First, we estimate an AR(2) model and a GARCH-M(1,1) model for the shares. Then, we estimated our AR(2) model with time varying coefficients and GARCH type errors. We find varying levels of efficiency and varying speeds of movement towards efficiency within our sample of four shares.     

Civil War and the Social Contract

In this contract-theoretic modelthe government promises a transfer to itspotential opponent in return for notengaging in a civil war. Two causes ofcivil war are identified: (i) imperfectcredibility increases the cost of therequired transfer, and may make itunfeasible; (ii) asymmetric informationfaces the government with the classicefficiency/rent-extraction trade off, andcivil war is used as a screening device.This problem can be solved by creating amixed army. The model determines whether amilitary regime or a redistributive stateprevails in a peaceful equilibrium. Astatistical illustration is presented,using African data.     

Rehumanizing Birth and Death in America

THESIS: Despite spending more on medical care than any other country in the world, the United States still boasts some of the worst patient outcomes of any developed nation. This disparity is especially true of how Americans give birth and die.  These natural human transitions have become catastrophically expensive and leave patients and their families traumatized from unnecessary interventions. This article examines the costs and outcomes associated with the medicalization of birth and death and argues that alternatives exist that improve patient outcomes while lowering costs. Access to these alternatives will require changing current regulatory and reimbursement structures and providing trained support staff to help families navigate beginning- and end-of life decisions.