Models of social mobility

Properties of measures and models of social mobility are analyzed in relation to the conceptualization of mobility. Two main objectives of mobility research are identified. One is the study of determinants of occupational achievement, the other is the study of mobility as a characteristic of social systems. It is shown that the realization of both objectives is hindered by a failure of commonly used models and measures of mobility to separate out the various individual and structural factors responsible for mobility.     

Division of Responsibility in Care of the Aged

Not all elderly people need special care. This review refers to the dependent minority and to the services they need. Brief mention is made of the history of services which began with charitable relief by voluntary action, and the current relationship between government bodies and voluntary agencies is outlined. It is maintained that division of responsibility for the various types of care should be based on assessment of individual needs, decentralization of control, together with evaluation of the resources of the agencies concerned.     

PROBLEMS OF THE POST-WAR PUBLIC: SOLDIERS AND CITIZENS

THE recent British White Paper on post-war education in Englandleaves little doubt that Britain looks to a new era of education.The work has already begun. The British soldier of today willbe the key citizen of tomorrow. Cognizant of this fact, theBritish War Office has established a far-reaching program ofeducation for citizenship among England's troops. It is being carried out by the Army Educational Corps. Thisarticle is the story of their work. Mr. Bickersteth, educated at Christ Church, Oxford, and theUniversity of Paris, is Director of Army Education in the BritishWar Office. He is on leave as Warden of Hart House, Universityof Toronto.     

The Practical Significance of Measurement Error in Pulmonary Function Testing Conducted in Research Settings

Conventional spirometry produces measurement error by using repeatability criteria (RC) to discard acceptable data and terminating tests early when RC are met. These practices also implicitly assume that there is no variation across maneuvers within each test. This has implications for air pollution regulations that rely on pulmonary function tests to determine adverse effects or set standards. We perform a Monte Carlo simulation of 20,902 tests of forced expiratory volume in 1 second (FEV₁), each with eight maneuvers, for an individual with empirically obtained, plausibly normal pulmonary function. Default coefficients of variation for inter‐ and intratest variability (3% and 6%, respectively) are employed. Measurement error is defined as the difference between results from the conventional protocol and an unconstrained, eight‐maneuver alternative. In the default model, average measurement error is shown to be ～5%. The minimum difference necessary for statistical significance at p < 0.05 for a before/after comparison is shown to be 16%. Meanwhile, the U.S. Environmental Protection Agency has deemed single‐digit percentage decrements in FEV₁ sufficient to justify more stringent national ambient air quality standards. Sensitivity analysis reveals that results are insensitive to intertest variability but highly sensitive to intratest variability. Halving the latter to 3% reduces measurement error by 55%. Increasing it to 9% or 12% increases measurement error by 65% or 125%, respectively. Within‐day FEV₁ differences ≤5% among normal subjects are believed to be clinically insignificant. Therefore, many differences reported as statistically significant are likely to be artifactual. Reliable data are needed to estimate intratest variability for the general population, subpopulations of interest, and research samples. Sensitive subpopulations (e.g., chronic obstructive pulmonary disease or COPD patients, asthmatics, children) are likely to have higher intratest variability, making it more difficult to derive valid statistical inferences about differences observed after treatment or exposure.