Measuring opinion distributions

In this study it will be argued that the perceived distribution of opinions among others is important for opinion research. Three different ways of measuring the perception of opinion distributions in survey research are compared: (a) by means of a questionwhat most people think about an issue, (b) by means of a questionhow many people are perceived to agree with an issue-statement, (c) by means of ‘line-production-boxes’, a special version ofmagnitude estimation. The results indicate that ‘line-production-boxes’ can improve data quality, but have also some drawbacks which will have to be dealt with. ‘Line-production-boxes’ give a wealth of information about individual differences in the forms of perceived opinion distributions. Although the normal distribution is used often, many other distribution forms are also used. The method of ‘line-production-boxes’ is compared with the method of estimating percentage points. Although high correlations suggest a good concurrent validity, some systematic differences do exist. New research directions are suggested.     

Mandatory Pensions and Personal Savings in The Netherlands*

The Netherlands has a relatively generous social security system and a wide coverage of individuals by private (occupational) pension schemes. Total household savings are rather high and fairly stable, although the amount of contractual savings apears to be going up at the expense of non-contractual (free) savings. Using an approach originally pioneered by Feldstein (1974) we employ microdata to investigate the displacement effect of security and pension wealth on free household savings. It turns out that the data available are too noisy to make precise statements about the displacement effects. Our results do suggest, however, that a one-for-one displacement of free savings by social security is consistent with the data. For pensions such a complete offset is less likely. This suggests that increase of coverage by private pensions is an effective way of raising savings.     

The estimation of utility‐consistent labor supply models by means of simulated scores

We consider a utility‐consistent static labor supply model with flexible preferences and a nonlinear and possibly non‐convex budget set. Stochastic error terms are introduced to represent optimization and reporting errors, stochastic preferences, and heterogeneity in wages. Coherency conditions on the parameters and the support of error distributions are imposed for all observations. The complexity of the model makes it impossible to write down the probability of participation. Hence we use simulation techniques in the estimation. We compare our approach with various simpler alternatives proposed in the literature. Both in Monte Carlo experiments and for real data the various estimation methods yield very different results. Copyright © 2008 John Wiley & Sons, Ltd.     

Tight LP-based lower bounds for wavelength conversion in optical networks

With the introduction of optical switching technology in telecommunication networks, all-optical connections, so-called lightpaths, can be established. Lightpaths have to be assigned a wavelength in such a way that no two lightpaths sharing a fiber use the same wavelength. The wavelength of operation can only be exchanged by the deployment of a wavelength converter. In this paper, we study the minimum converter wavelength assignment problem. We develop three integer programming formulations to minimize the number of converters and study their properties. Where the first two formulations lack the power to provide non-trivial lower bounds, tight lower bounds can be computed by solving the linear relaxation of the third formulation by delayed column generation. In fact, the lower bound equals the best known solution value for all realistic instances at our disposal. In a computational study, we compare different strategies to enhance the column generation algorithm.     

Absenteeism in Israeli schoolteachers: An organizational ethics perspective

Two studies are presented with the purpose of investigating teacher absences in Israel from the perspectives of organizational normative behavior (Study 1) and organizational ethical climate (Study 2). Study 1 posits that absence may represent shirking behavior, and tested this hypothesis by investigating temporal absence trends of the entire public teacher population in Israel around weekends, holidays, and days of heavy workload. Results provide evidence which supports our theoretical expectations. Study 2 proposes that teachers' work absences are associated with the school's ethical climate. Using a sample of high-school teachers, our results supported this hypothesis, particularly for low-seniority and non-tenured teachers. We suggest that the normative behavior and ethical climate perspectives offer new vistas for advancing our understanding of absence behavior in organizations.     

Explaining the wealth holdings of different cohorts: Productivity growth and Social Security

In this paper, we explore the reasons why different generations accumulate different amounts of wealth. We use basic economic theory to propose two indicators of the economic conditions under which households accumulate wealth. The first one represents productivity differences across cohorts: The aggregate level of gross national product per capita around the time the head of the household entered the labor market. The second measure summarizes the changes in Social Security during the head of household's working life. Using panel data from the Dutch Socio-Economic Panel, we show that productivity growth can explain all the cohort effects present in income data, while productivity growth and the generosity of Social Security can explain all the cohort effects present in household net worth. We also find a limited offset of Social Security on wealth holdings.     

Primacy in stock market participation: the effect of initial returns on market re-entry decisions

We examine whether initial returns influence investors’ decisions to return to the stock market following withdrawal. Using a survival analysis technique to estimate Finnish retail investors’ likelihood of stock market re-entry reveals that investors who experience lower initial returns are less likely to return, even after controlling for returns in the last month and average monthly returns for the duration of investing. This primacy effect is robust to accounting for endogeneity in investors’ exit decisions, and other behavioural biases such as recency and saliency of investment experience. Individual investors appear to be subject to primacy bias and tend to put a significant weight on initial experiences in re-entry decisions.