A play-the-winner-type urn design with reduced variability

We propose a new adaptive allocation rule, the drop-the-loser, that randomizes subjects in the course of a trial comparing treatments with dichotomous outcomes. The rule tends to assign more patients to better treatments with the same limiting proportion as the randomized play-the-winner rule. The new design has significantly less variable allocation proportion than the randomized play-the-winner rule. Decrease in variability translates into a gain in statistical power. For some values of success probabilities the drop-the-loser rule has a double advantage over conventional equal allocation in that it has better power and assigns more subjects to the better treatment. Acknowledgments. I thank Stephen Durham, the associate editor, and the referees for their helpful suggestions.     

Is the Optimal Labor Income Tax Progressive in a Unionized Economy?*

This paper concerns optimal nonlinear labor income taxation in an economy with union wage setting and endogenous hours of work. The purpose is to study the determinants of tax progression. We show that the optimal degree of progression of the labor income tax depends on the extent to which the government can influence the wage rate via tax policy as well as on its ability to redistribute income across individuals. In addition, the argument for progressive labor income taxation depends on whether hours of work are chosen by the employed themselves or the union.     

Income and substitution effects of fiscal policy on work effort

The focus of this paper is twofold. First, it examines the impact on work effort of changes in government purchases financed with lump‐sum taxes, in a neoclassical framework, with respect to four industrialised countries. Second, it reconsiders the expenditure–work effort relationship in a broader conceptual context that allows for distortionary taxation and a disaggregation of the income and substitution effects. Our findings are shown to cast doubt on the empirical plausibility of the prevailing (neoclassical and New Keynesian) models which seem to rely heavily on the lump‐sum tax notion, thus ignoring the substitution effects of distortionary taxation.     

Allocating an advertising budget to international travel markets

Deciding on advertising appropriations is a common problem to all National Tourist Offices. The Austrian National Tourist Office now employs a decision support model allowing for inclusion of managerial judgments. In tourism, like elsewhere, application of standard optimization routines to marketing decision making is straight- forward, once the relationship linking market response to input has been modeled adequately. A tailor-made decision calculus procedure eliciting managerial judgments on the relative importance of the factors determining a receiving country's travel market share provides the weights otherwise inaccessible by objective parameter estimation. A tourism manager thus can evaluate countries as tourism generators and allocate an advertising budget accordingly.     

Cities under stress

This paper studies the effect of terrorist attacks on the internal structure of cities. We develop an urban framework with capital structures suitable for the study of this question and analyze the long and short term implications of this type of events. In the long run, the analysis shows that a terrorist attack will affect urban structure only modestly, relative to the potentially large decrease in the level of economic activity in the city. Land rents will not decline at all locations. In the short run, agglomeration forces will amplify the effect of the original destruction and will reduce urban economic activity temporarily.     

Unit roots and infrequent large shocks: new international evidence on output

The nature and magnitude of the economic shocks that have affected the per capita GDP of 16 OECD countries are analyzed over a long period using the outlier method. Strong proof of infrequent large permanent and transitory shocks were found, essentially resulting from the two major wars in the twentieth century, the recession in the 1920s, the Great Depression, among others. We also examine the nature of the output trend by combining different tests of non-stationarity on different GDP series corrected by the outliers detected. It is shown that the per capita GDP series cannot reject the unit root hypothesis in 13 of the 16 countries examined. No conclusion could be drawn for the other countries because the test results were contradictory.     

METROPOLITAN HOUSE PRICES IN SOUTH AFRICA: DO THEY CONVERGE?

The question this paper investigates is whether or not different metropolitan areas each constitute a separate housing market or whether or not there is a single South African housing market. Theory on the Law of One Price suggests that if products or geographic areas belong in the same market, their absolute prices must converge, so that their relative prices are stationary. By using cross-sectional time series data of five metropolitan areas, the paper tests for the Law of One Price by applying the Im, Pesaran and Shin panel unit root test. The paper finds strong evidence of convergence in large middle-segment house prices and weaker support for convergence in medium middle-segment house prices. In addition, the paper finds no evidence for convergence in small middle-segment house prices. This suggests the existence of a national market for large and possibly middle-segment houses in metropolitan areas, but separate metropolitan markets for small middle-segment houses. In addition, the paper estimates the speed of convergence and finds that large middle-segment house prices converge within two to seven quarters, while the speed of convergence for medium middle-segment house prices in three of the five areas is five to eight quarters.