Stability and agreement criteria for the termination of Delphi studies

This paper addresses the question of the methodology of testing for stability between successive Delphi rounds and the necessity of doing so prior to the analysis of the level or type of consensus. Following a discussion of a hierarchical set of a criteria for determining the termination of such studies, the paper reviews some of the more common treatments of the subject in the literature. It is finally proposed that a χ² test be used to test the stability of responses between rounds. The method is demonstrated by a numerical example.     

Policy Discrimination with and without Interpersonal Comparisons of Utility

Can the Pareto criterion guide policymakers who do not know the true model of the economy? If policymakers specify ex ante preferences for agents, then Pareto improvements from a distorted status quo are usually possible, and with more commodities than states, one can implement almost every Pareto optimum. Unlike the standard second welfare theorem, planners cannot dictate allocations: agents must trade. Unfortunately ex ante preferences impose interpersonal comparisons. If policymakers merely aim to maximize some social welfare function then optimal policies form an open set; hence small changes in the environment do not necessitate any policy response. Planners with symmetric information about agents can sometimes intervene without making interpersonal comparisons.     

Taxation and top incomes in Canada

We estimate the elasticity of reported income with respect to tax rates for high earners using sub‐national variation across Canadian provinces. We argue this allows for better identification of tax elasticities than the existing literature. We find that elasticities of reported income at the provincial level are large for incomes in the top 1%, but small for lower earners. There are strong indications that the response happens both through earned and capital income. While our estimated elasticities are large, changes in tax rates cannot explain much of the overall long‐run trend of higher income concentration in Canada.     

Explaining Growth: A Contest Between Models

Recent contributions to the empirical growth literature show no tendency to convergence in specification, as researchers seek to identify new variables that can account for significant regional effects in earlier work. We conduct non-nested tests between the models of Barro (1997), Easterly and Levine (1997) and Sachs and Warner (1997). The data strongly prefer an encompassing model, but fail to reject any of the candidate models, implying that each model represents a partial truth. We identify a model that includes most (but not all) of the regressors in the candidate models and is robust to the inclusion of regional dummies.     

A profitable trading and risk management strategy despite transaction costs

We present a new profitable trading and risk management strategy with transaction cost for an adaptive equally weighted portfolio. Moreover, we implement a rule-based expert system for the daily financial decision-making process using the power of spectral analysis. We use several key components such as principal component analysis, partitioning, memory in stock markets, percentile for relative standing, the first four normalized central moments, learning algorithm, and switching among several investment positions consisting of short stock market, long stock market and money market with real risk-free rates. We find that it is possible to beat the proxy for the equity market without short selling for 168 S&P 500-listed stocks during the 1998–2008 period and 213 Russell 2000-listed stocks during the 1995–2007 period. Our Monte Carlo simulation for both the various set of stocks and the interval of time confirms our findings.     

The fragility of information aggregation in large elections

In a common-values election where voters receive a signal about which candidate is superior, suppose there is a small amount of uncertainty about the conditional likelihood of the signal?s outcome, given the correct candidate. Once this uncertainty is resolved, the signal is i.i.d. across agents. Information can then fail to aggregate. The candidate less likely to be correct given agents? signals can be elected with probability near 1 in a large electorate even if the distribution of signal likelihoods is arbitrarily near to a classical model where agents are certain that a particular likelihood obtains given that a specific candidate is correct.