Minimum Death Rates and Maximum Life Expectancy: The Role of Concordant Ages

Only five populations have achieved maximum life expectancy (or best practice population) more than occasionally since 1900. The aim of this article is to understand how maximum life expectancy is achieved in the context of mortality transition. We explore this aim using the concepts of potential life expectancy, based on minimum rates at each age among all high longevity populations, and concordant ages. Concordant ages are defined as ages at which the minimum death rate occurs in the population with the maximum life expectancy. The results show the extent to which maximum life expectancy could increase through the realization of demonstrably achievable minimum rates. Concordant ages are concentrated at increasingly older ages over time, but they have produced more than half of the change in maximum life expectancy in almost all periods since 1900. This finding is attributed to their quantity and position whereby concordant ages are concentrated at the ages that have the greatest impact on mortality decline in a particular period. Based on mortality forecasts, we expect that concordant ages will continue to lead increases in female maximum life expectancy, but that they will play a weaker role in male maximum life expectancy.     

Market structure and bid-ask spreads: IBIS vs Nasdaq

A comparison is made between the bid-ask spreads of 30 high volume German stocks traded on IBIS and 30 high volume US stocks traded on Nasdaq. IBIS and Nasdaq are best described as agency and dealer auction markets, respectively. On average, the market spread for these IBIS and Nasdaq stocks is the same, but for the 10 most active stocks in each market, IBIS spreads are considerably lower. For these latter stocks, IBIS spreads change in a predictable manner throughout the day. Nasdaq spreads do not. The critical factor appears to be the unrestricted access of suppliers of immediacy that is distinctive for agency auction markets.     

Performance-weighted ensembles of random forests for predicting price impact

For any large player in financial markets, the impact of their trading activity represents a substantial proportion of transaction costs. This paper proposes a novel machine learning algorithm for predicting the price impact of order book events. Specifically, we introduce a prediction system based on ensembles of random forests (RFs). The system is trained and tested on depth-of-book data from the BATS and Chi-X exchanges and performance is benchmarked using ensembles of other popular regression algorithms including: linear regression, neural networks and support vector regression. The results show that recency-weighted ensembles of RFs produce over 15% greater prediction accuracy on out-of-sample data, for 5 out of 6 timeframes studied, compared with all benchmarks. Feature importance ranking is used to explore the significance of various market features on the price impact, finding them to be highly variable through time. Finally, a novel procedure for extracting the directional effects of features is proposed and used to explore the features most dominant in the price formation process.     

Work and Volunteering: Longitudinal Relationships between Work‐Related Experiences and Volunteering Behaviour

This study examines the effect of work‐related experiences on employees’ engagement in community volunteering, using data from a British longitudinal panel of employees. Using a novel analytical approach that separates variation in volunteering due to within‐person changes in work conditions from variation due to between‐person work differences, we more robustly test existing and new hypotheses about the effects of work on volunteering. New to this literature, we find that commuting and satisfaction with job experiences are significant predictors of community volunteering, both the likelihood to volunteer and volunteering frequency. In turn, volunteering determinants previously explored with cross‐sectional data, such as managerial and professional jobs, employment sector and hourly paid contracts, are no longer statistically significant in the within‐person models. We discuss a number of important theoretical and practical consequences of these findings.     

Union coverage and non-standard work in Britain

Using representative data from the British Household Panel Surveyfor the period 1991–97, we document the extent of unioncoverage across standard and non-standard workers in Britain.Non-standard employment—defined in terms of contracts,places, times, and hours of work—involves approximately60% of the employed population. Most workers in non-standardemployment are less likely to be union covered than otherwiseidentical workers in standard employment. In particular, womenacross nearly all types of non-standard jobs are significantlyless likely to be covered than women in regular employment.For men, this negative relationship is only found for thoseworking on fixed term contracts or short hours. Gender differencesare therefore large and significant. We cannot detect an expansionof union coverage towards any type of non-standard employmentover our sample period. Finally, we find significant differencesin the relationship between non-standard work and union coveragein the private and public sectors.     

The Role of Long-Term Finance: Theory and Evidence

Improving the supply of long-term credit to industrial firmsis considered a priority for growth in developing countries.A World Bank multicountry study looks at whether a long-termcredit shortage exists and, if so, whether it has had an impacton investment, productivity, and growth. The study finds thateven after controlling for the characteristics of individualfirms,businesses in developing countries use significantly less long-termdebt than their counterparts in industrial countries. Researchersare able to explain the difference in debt composition betweenindustrial and developing countries by firm characteristics;by macroeconomic factors; and, most importantly, by financialdevelopment, government subsidies, and legal and institutionalfactors. The analysis concludes that long-term finance tends to be associatedwith higher productivity. An active stock market and an abilityto enter into long-term contracts also allow firms to grow atfaster rates than they could attain by relying on internal sourcesof funads and short-term credit alone. Importantly, althoughgovernment-subsidized credit markets have increased the long-termindebtedness of firms, there is no evidence that these subsidiesare associated with the ability of firms to grow faster. Indeed,in some cases subsidies are associated with lower productivity.      

A sticky floors model of promotion, pay, and gender

According to raw data from the British Household Panel Survey, full-time women are more likely than men to be promoted. Controlling for observed and unobserved individual heterogeneity, we find that women are promoted at roughly the same rate as men, but may receive smaller wage increases consequent upon promotion. To help explain these phenomena, we construct a new “sticky floors” model of pay and promotion. In our model, women are just as likely as men to be promoted but find themselves stuck at the bottom of the wage scale for the new grade.