Tempering effects of (dependent) background risks: A mean-variance analysis of portfolio selection

In a mean variance framework, we analyse risk taking in the presence of a (possibly) dependent background risk, exemplified in a linear portfolio selection problem. We first characterise the comparative statics of changes in the distribution and dependence structure of the background risk. For unfair, undesirable and loss-aggravating increases in background risks (both dependent and independent), we then present necessary and sufficient restrictions on preferences such that greater background uncertainty leads to reduced risk taking. With mean-variance preferences, these restrictions boil down to simple conditions on the marginal rate of substitution between risk and return. They can be easily related to familiar notions such as risk vulnerability, properness or standardness.     

Dynamic Costs of the Draft

Abstract. We propose a dynamic general‐equilibrium model with human capital accumulation to evaluate the economic consequences of compulsory services (such as military draft or social work). Our analysis identifies a so far ignored dynamic cost arising from distortions in time allocation over the life cycle. We provide conservative estimates for the excess burden that arises when the government relies on forced labor rather than on income taxation to finance public expenditures. Our results suggest that eliminating the draft could produce considerable dynamic gains, both in terms of GDP and lifetime utility.     

Combining forecasts: An application to elections

We summarize the literature on the effectiveness of combining forecasts by assessing the conditions under which combining is most valuable. Using data on the six US presidential elections from 1992 to 2012, we report the reductions in error obtained by averaging forecasts within and across four election forecasting methods: poll projections, expert judgment, quantitative models, and the Iowa Electronic Markets. Across the six elections, the resulting combined forecasts were more accurate than any individual component method, on average. The gains in accuracy from combining increased with the numbers of forecasts used, especially when these forecasts were based on different methods and different data, and in situations involving high levels of uncertainty. Such combining yielded error reductions of between 16% and 59%, compared to the average errors of the individual forecasts. This improvement is substantially greater than the 12% reduction in error that had been reported previously for combining forecasts.     

GOVERNMENT SIZE AND GROWTH: A SURVEY AND INTERPRETATION OF THE EVIDENCE

Abstract The literature on the relationship between the size of government and economic growth is full of seemingly contradictory findings. This conflict is largely explained by variations in definitions and the countries studied. An alternative approach – of limiting the focus to studies of the relationship in rich countries, measuring government size as total taxes or total expenditure relative to GDP and relying on panel data estimations with variation over time – reveals a more consistent picture. The most recent studies find a significant negative correlation: an increase in government size by 10 percentage points is associated with a 0.5% to 1% lower annual growth rate. We discuss efforts to make sense of this correlation, and note several pitfalls involved in giving it a causal interpretation. Against this background, we discuss two explanations of why several countries with high taxes seem able to enjoy above average growth. One hypothesis is that countries with higher social trust levels are able to develop larger government sectors without harming the economy. Another explanation is that countries with large governments compensate for high taxes and spending by implementing market‐friendly policies in other areas. Both explanations are supported by ongoing research.     

Low interest rate policy and the use of reserve requirements in emerging markets

This paper sheds light on the link between the interest rate policy in large advanced economies with international funding and reserve currencies (the United States and the euro area) and the use of reserve requirements in emerging markets. Using reserve requirement data for 28 emerging markets from 1998 to 2012, we provide evidence that emerging market central banks tend to raise reserve requirements when interest rates in international funding markets decline or financial inflows accelerate, most likely to preserve financial stability. In contrast, when global liquidity risk rises and funding from the large advanced economies dries up, emerging markets lower reserve requirements.     

Comparing face-to-face meetings, nominal groups, Delphi and prediction markets on an estimation task

We conducted laboratory experiments for analyzing the accuracy of three structured approaches (nominal groups, Delphi, and prediction markets) relative to traditional face-to-face meetings (FTF). We recruited 227 participants (11 groups per method) who were required to solve a quantitative judgment task that did not involve distributed knowledge. This task consisted of ten factual questions, which required percentage estimates. While we did not find statistically significant differences in accuracy between the four methods overall, the results differed somewhat at the individual question level. Delphi was as accurate as FTF for eight questions and outperformed FTF for two questions. By comparison, prediction markets did not outperform FTF for any of the questions and were inferior for three questions. The relative performances of nominal groups and FTF were mixed and the differences were small. We also compared the results from the three structured approaches to prior individual estimates and staticized groups. The three structured approaches were more accurate than participants’ prior individual estimates. Delphi was also more accurate than staticized groups. Nominal groups and prediction markets provided little additional value relative to a simple average of the forecasts. In addition, we examined participants’ perceptions of the group and the group process. The participants rated personal communications more favorably than computer-mediated interactions. The group interactions in FTF and nominal groups were perceived as being highly cooperative and effective. Prediction markets were rated least favourably: prediction market participants were least satisfied with the group process and perceived their method as the most difficult.     

Encouraging employees to co-operate: the effects of sponsored training and promotion practices on employees' willingness to work overtime

The ‘mutual-investment’ model argues that when employers invest more in the social exchange relationship between them and their employees, their employees will show more effort. In this paper we relate the ‘mutual-investment’ model to training and promotion (possibilities) and examine if these kinds of career-enhancing measures influence the willingness of employees within organizations to work overtime. To test this hypothesis, a vignette experiment was conducted in five organizations (N = 388; 1,531 vignettes). Multilevel analyses show that employees are more willing to work overtime when their employer has provided for training, when the employee recently was promoted, when the supervisor was supportive in the past and when co-workers approve of working overtime and behave similarly. But we did not find that future promotion chances affect willingness to work overtime.