Changes In Observable Characteristics Research Articles

Job-to-Job Transitions, Job Finding and the Ins of Unemployment

Increases in the ins of unemployment during recessions are the result of two major forces: increased layoffs, or a fall in job finding of potential job-to-job transitions. This paper quantifies the contribution of these two channels using the flows approach to the labour market in the UK and US over a period of two decades. The results show that fluctuations in job finding of potential job-to-job transitions are at least as important as layoffs, but that layoffs were particularly important in the Great Recession in US. The results suggest that around three-quarters of unemployment dynamics are explained by fluctuations in job finding. I show that these findings are not driven by compositional changes in observable characteristics, and are robust to an adjustment for time-aggregation. I provide new evidence, consistent with these results, regarding changes in search incidence before match dissolution in the UK.

WAGE SIGNALING: A DYNAMIC MODEL OF INTRAFIRM BARGAINING AND ASYMMETRIC LEARNING

The article analyzes the effect of employer–worker bargaining on wage dynamics in the presence of asymmetric information between current and potential employers. A failure to reach an agreement leads to output loss. Because the disagreement points depend upon the worker's productivity, productive workers separate themselves from less productive workers and signal their ability through wages. In existing models of asymmetric learning, wages are attached to publicly observable characteristics and wage growth occurs only when there is a change in observable characteristics. This model, in contrast, generates an increase in earnings dispersion in cohorts of workers with similar observable characteristics.

Patterns of ethnic self-employment in time and space: evidence from British Census microdata

The over-representation of certain ethnic minority and immigrant groups in self-employment is, in common with other developed countries, a notable feature of the UK labour market. Compared to the substantial growth in self-employment in the 1980s, the 1990s saw overall self-employment rates plateau. Despite this, some minority groups experienced continued growth whilst others, particularly Chinese and Indian males and Pakistani, Bangladeshi and Chinese females, saw their self-employment rates decline. In this paper we use microdata samples from the 1991 and 2001 Censuses to investigate the dynamic and spatial patterns of ethnic entrepreneurship. Using decomposition methods we find that, for males from the Asian groups, changes in observable characteristics associated with an increasing proportion of second-generation individuals explain much of the decline in self-employment. This, which is also true of Chinese females, reflects in part the age structure and educational experiences of the second generation. The dynamics of Black male and Pakistani/Bangladeshi male and female entrepreneurship are less easy to explain. We also find that, while there is no evidence of self-employment being an “enclave” phenomenon, local economic conditions do affect rates of entrepreneurship for some groups, notably Pakistanis and Bangladeshis.

Dropping out of medical school in the UK: explaining the changes over ten years

In the context of changing admissions criteria and an expanding medical school intake in the UK, we analysed the determinants of the medical school dropout probability. We aimed to analyse the determinants of the probability that a student will drop out of medical school during Year 1 and to compare the results of this analysis over time. We carried out logistic regression analysis for the 6 intake cohorts of 1990-92 and 1998-2000. Between 1990-92 and 1998-2000, there were substantial increases in both the size of the entry cohort and the proportion of students dropping out of medical school. A logit model for the 1990-92 and 1998-2000 cohorts reveals that the probability of dropping out depended on both the medical school attended and the personal characteristics of the student, including academic preparedness. Almost none of the increase in the dropout rate between the 2 cohort groups can be explained by changes in observable characteristics of the students over this period. Instead, most of the increase in the dropout rate is associated with changes at the level of the institution and in unobserved student characteristics. University effects, rather than changes in observed student characteristics, explain most of the increased dropout rate over the time period considered. Candidate explanations behind these effects include: less effective admissions policies; changing curricula; greater costs of attending medical school, and a growing mismatch between student and school characteristics. Testing between these competing hypotheses is left for future work.

Has Working More Caused Married Women to Volunteer Less? Evidence from Time Diary Data, 1965 to 1993

Now that married women are working more for pay than they were three decades ago, are they less likely to volunteer? I use national time diary surveys conducted in 1965, 1975, 1985, and 1993 to document a decrease in the weekly volunteer participation rate of working-age married women, from 16.4% in 1965 to 9.3% in 1993. Changes in observable characteristics explain about 65% of the decrease in married women’s volunteer participation from 1965 to 1985. The increased employment rates of married women as well as the changes in their parental status are substantial contributors to the decline in their volunteer participation. Married women’s gain in educational attainment is the most important factor to offset the decline in their volunteer participation. However, married women’s changing labor force and parental status do not explain why married women’s volunteer participation continued to decline from 1985 to 1993.

Historical development of cell and tissue culture freezing

In conclusion, the use of glycerol or dimethyl sulfoxide has permitted successful freezing, storage, and thawing of most, but not all, animal cell cultures. Storage in liquid nitrogen without detectable change in observable characteristics appears to be indefinite. Methods are empiric, understanding of the basic physics and chemistry involved are fragmentary, and results cannot always be exactly duplicated within one laboratory or in different laboratories. These problems will be solved in the future by the combined application of many disciplines with overlapping interests in molecular biology. In the meantime, present methods permit indefinite cold storage of most cell cultures with a great saving in labor and inconvenience, while avoiding accidental loss, contamination, or mutation of the cells during repeated serial passage.