APPROPRIABLE RENTS FROM YELLOWSTONE PARK: A CASE OF INCOMPLETE CONTRACTING

The history of Yellowstone Park is best understood in the context of the theory of the firm as developed by Armen Alchian. In the late nineteenth century, the Northern Pacific Railroad recognized the potential amenity rents from Yellowstone and captured them by vertically integrating its monopoly on transportation to the region with the supply of tourist facilities in the park. This gave the railroad de facto ownership of the park that lasted until automobiles were allowed to enter in 1915. Thereafter the tragedy of the commons ensued and rents were dissipated instead of maximized.     

Infant‐Directed Speech Facilitates Word Segmentation

There are reasons to believe that infant‐directed (ID) speech may make language acquisition easier for infants. However, the effects of ID speech on infants' learning remain poorly understood. The experiments reported here assess whether ID speech facilitates word segmentation from fluent speech. One group of infants heard a set of nonsense sentences spoken with intonation contours characteristic of adult‐directed (AD) speech, and the other group heard the same sentences spoken with intonation contours characteristic of ID speech. In both cases, the only cue to word boundaries was the statistical structure of the speech. Infants were able to distinguish words from syllable sequences spanning word boundaries after exposure to ID speech but not after hearing AD speech. These results suggest that ID speech facilitates word segmentation and may be useful for other aspects of language acquisition as well. Issues of direction of preference in preferential listening paradigms are also considered.     

Some subjective bayesian considerations in the selection of models

Some considerations relating to the post-data selection of models are discussed. These include some difficulties with orthodox theory, implementation of the likelihood principle, and Bayesian tests of hypotheses.     

Moving the participation agenda forward

This article sets the scene for the other papers in this Special Issue on children's and young people's participation, by outlining the nature of the ESRC Seminar Series from which all are derived and by developing the main themes discussed at the seminars. The focus of this Issue is participation by children and young people as this relates to differing notions of social exclusion and inclusion. This article critically examines participation in the contexts of policy, practice, research and theory. In many respects the environments in each of these domains is supportive of increased participation, yet there is also much evidence of limited impact by recent participative measures and of disillusionment by many young people who have been engaged in consultation and decision‐making. A way forward is suggested, which entails collaboration among all the key stakeholders including children and young people, connects participatory and social inclusion aims and mechanisms, and is committed to achieving tangible outcomes based on the wishes of children and young people.     

Medication for Children with Attention-Deficit Hyperactivity Disorder

When making assessments and planning interventions, social workers adopt a biopsychosocial perspective. One important area where biologically based treatments influence psychosocial functioning is the area of psychopharmacology. However, even though many clients take medications, social workers often feel poorly prepared to address a subject that could be very important to their clients; that subject is the meaning of the medication to the client. The meanings that clients ascribe to medication can have a significant impact on medication adherence. Using attention-deficit/hyperactivity disorder (ADHD) to illustrate, I provide an overview of ADHD and common forms of treatment, discuss the possible meanings and acceptability of stimulant treatment for ADHD, provide practice guidelines for helping families reduce ambivalence about medication, present two clinical vignettes, and suggest resources for social workers and families.     

Fertility and mortality estimation from the Panama Retrospective Demographic Survey, 1976

Summary Data from the Retrospective Demographic Survey of Panama offer a unique opportunity to test a wide range of methods for estimating indirectly basic demographic parameters from inaccurate and incomplete data. Our primary emphasis is to evaluate methods for estimating adult mortality from information on widowhood and orphanhood, though estimates of childhood mortality obtained from information on sibling and child survivorship are assessed as well. The results for most of the estimating procedures are consistent; this finding is encouraging because it lends support to the hypothesis that the techniques can provide good estimates of mortality. Methods which produce results which are inconsistent provide valuable lessons. In particular, methods for providing unconditional estimates of values ofl (x) for adults by combining directly information on childhood mortality and adult mortality are shown to produce estimates which predominantly reflect the level of childhood mortality employed. Furthermore, within-method consistency of estimates appears to be a very poor indicator of reliable performance of the estimating technique or quality of data, since most methods yielded estimates which were internally consistent, though estimates made by different methods could differ considerably. In summary, the analysis indicates a birth rate of around 35 per thousand, a death rate of around 7.5 per thousand, a total fertility ratio of about 4.8, and expectations of life at birth of approximately 59 and 64 years for men and women respectively.     

New approaches to the estimation of migration flows from census and administrative data sources

Census data represent an important source of information about migration flows. However, existing estimation procedures based on intercensal projection are often inconvenient to apply and are sensitive to even quite small changes in enumeration completeness. 2 new estimation procedures applicable to data from 2 censuses are developed and illustrated using US data. The 1st method is essentially a modification of traditional intercensal projection techniques, but as a result of working with age groups rather than cohorts, it is simpler to apply and allows mortality of the migrants to be incorporated over the intercensal period. The 2nd method also uses information from 2 censuses, but also uses independent information on the age pattern of migration from administrative sources or from other census questions. The method uses the fact that the age pattern of recent migration is likely to be different from the age distribution of the overall population to distinguish between intercensal change due to migration and apparent intercensal change due to changes in enumeration completeness. If the method's assumptions are met, it is possible to estimate the relative coverage of the 2 censuses as well as the scale of the independent age pattern of migration relative to the coverage of 1 or other of the censuses. The illustrative applications of the methods to US data suggest that both can work reasonably well.