Fatigue effects of noise on aeroplane mechanics

Subjective fatigue and reaction time performance were measured in a group of 24 aeroplane mechanics, during 1 week of high noise exposure and 1 week of low noise exposure. Subjective ratings were collected before and after each work day. On the last day of each week subjects also completed a reaction time task before and after work. The mechanics felt more sleepy and less energetic during the high noise week. This effect was most evident towards the end of the day and there was a build-up of the effect during the week. Reaction times were prolonged during the high noise week. Possible confounding factors are discussed and found to be less likely explanations of the effects.     

Some statistical aspects of methods for detection of turning points in business cycles

Methods for online turning point detection in business cycles are discussed. The statistical properties of three likelihood-based methods are compared. One is based on a Hidden Markov Model, another includes a non-parametric estimation procedure and the third combines features of the other two. The methods are illustrated by monitoring a period of the Swedish industrial production. Evaluation measures that reflect timeliness are used. The effects of smoothing, seasonal variation, autoregression and multivariate issues on methods for timely detection are discussed.     

Monitoring cyclical processes. A non-parametric approach

Forecasting the turning points in business cycles is important to economic and political decisions. Time series of business indicators often exhibit cycles that cannot easily be modelled with a parametric function. This article presents a method for monitoring time-series with cycles in order to detect the turning points. A non-parametric estimation procedure that uses only monotonicity restrictions is used. The methodology of statistical surveillance is used for developing a system for early warnings of cycle turning points in monthly data. In monitoring, the inference situation is one of repeated decisions. Measurements of the performance of a method of surveillance are, for example, average run length and expected delay to a correct alarm. The properties of the proposed monitoring system are evaluated by means of a simulation study. The false alarms are controlled by a fixed median run length to the first false alarm. Results are given on the median delay time to a correct alarm for two situations: a peak after two and three years respectively .     

Perception of own death risk

Individuals’ perception of their own road-traffic and overall mortality risks are examined in this paper. Perceived risk is compared with the objective risk of the respondents’ peers, i.e. their own gender and age group, and the results suggest that individuals’ risk perception of their own risk is biased. For road-traffic risk we obtain similar results to what have been found previously in the literature, overassessment and underassessment among low- and high-risk groups, respectively. For overall risk we find that all risk groups underestimate their risk. The results also indicate that men's risk bias is larger than women’s.

Welfare state context,female labour-market attachment and childbearing in Germany and Denmark

This study investigates the role of female labour-market attachment and earnings in childbearing progressions in two very different European contexts. By applying event-history techniques to German and Danish register data during 1981–2001, we demonstrate how female earnings relate to first, second and third birth propensities. Our study shows that female earnings are positively associated with first birth fertility in Denmark, while this is not the case in West Germany. We interpret our findings based on the fact that Danish social context and policy encourage women to establish themselves in the labour market before becoming mothers, while the German institutional context during the 1980s and 1990s was not geared towards encouraging maternal employment. For higher-order births, the results are less clearcut. For Denmark we find a slightly positive correlation between female earnings and second-birth fertility, while the association is somewhat negative for third-order births. In Germany, women tend to leave the labour market when becoming mothers. Non-employed mothers have elevated second and, in particular, third-birth rates. For the group of mothers who are employed, we find only a weak association between their earnings and higher-order fertility.     

The Impact of Food Price Inflation on Subjective Well-being: Evidence From Urban Ethiopia

The world has experienced dramatic food price inflation in recent years, which sparked social unrest and riots in various developing countries. In this paper, we use a novel approach to measure the impact of food price inflation on subjective well-being of urban households in Ethiopia, a country which exhibited one of the highest rates of food price inflation during 2007–2008. Using an ordered probit regression, we show that being negatively affected by a food price shock reduced subjective well-being of households significantly, although the economy was growing rapidly. We also show that relative standing has a large negative effect on subjective well-being of respondents. The fact that rapid economic growth was accompanied by a decline in citizens’ average reported level of life satisfaction brings its pro-poorness into question. We argue that controlling the rise in food price and ensuring that economic growth trickles down to the average urban citizen would enhance welfare significantly.     

The value of improved road safety

We report the results of a contingent valuation study for finding a conservative estimate of the value-of-statistical-life in an urban road safety context in Sweden. We estimate the value of both a private-good device and a public-good safety program. The reduction of risk is communicated with a “community analogy” representation of the “Vision Zero” target of the national traffic-safety policy. According to this target, the road-traffic system should be designed so as to prevent accidents when they happen to lead to fatalities or severe injuries. We use the “certainty approach” for ex-post correction of results to remove or mitigate hypothetical bias of responses. As expected we find insensitivity of responses in the full sample to the size of the risk reduction being valued. By our approach we can compute a conservative estimate, based on answers from fully confident respondents, of the value of the largest possible safety enhancement (i.e. fulfilment of the “Vision Zero”). This lower bound estimate indicates a higher average willingness-to-pay for public safety-improving measures than currently assumed in benefit-cost assessments. We also find that the willingness to pay is considerably lower within a public-good than a private-good framework and a weak indication of sensitivity to scale among the most confident respondents. JEL Codes H43 · I18 · Q51     

“Touching up” Communal Space of a Residential Home Setting: A Comparative Study of Tools for Assessing Changes in the Interior Architectural Space

This study focuses on the interior remodeling of two Swedish residential homes for dependent seniors. A regular maintenance operation was turned into a color intervention project, and the residents stayed during the process. The aim of the study was to assess the changes in terms of supportiveness for elderly individuals with cognitive or functional impairments. The settings were evaluated prior to and after remodeling. Architecture profession method and the Therapeutic Environment Screening Survey of Nursing Homes instrument were used. The conclusion is that a supportive architecture was not achieved, due to a restraining focus on color instead of the relation between aging, color, and homeliness. On the other hand, the architecture profession method and the Therapeutic Environment Screening Survey of Nursing Homes instrument proved to be useful complementary tools for assessing interior changes in architectural space.     

Small Effects of Selective Migration and Selective Survival in Retrospective Studies of Fertility

In this study, we assess the accuracy of fertility estimates that stem from the retrospective information that can be derived from an existing cross-sectional population. Swedish population registers contain information on the childbearing of all people ever registered as living in Sweden, and thus allow us to avoid problems of selectivity by the virtue of survival or nonemigration when estimating the fertility measures for previous calendar periods. We calculate two types of fertility rates for each year in 1961–1999: (i) rates that are based on the population that was living in Sweden at the end of 1999, and (ii) rates that also include information on people who had died or emigrated before the turn of the twentieth century. We find that the omission of information on individuals who had emigrated or died, as the situation would be in any demographic survey, most often have negligible effects on fertility measures. However, first-birth rates of immigrants gradually become more biased as we move back in time from 1999 so that they increasingly tend to over-estimate the true fertility of that population.