Income Diversity,Technology Choice and Agricultural Research Policy in Sub‐Saharan Africa

This article makes an initial analysis of the implications of income diversification for technical change and agricultural research policy in Africa, leading to two insights. First, that the dilution effect of income diversification means that, as the proportion of non‐farm income increases, so must the expected gains from adopting a new agricultural technology. Second, that diversified producers will face disproportionately large transactions costs associated with information acquisition to inform technology choice decisions. Two hypotheses about how diversified producers are likely to react are then explored. Both point to the conclusion that income diversification among the poor is likely to constrain significantly the direct poverty impacts of agricultural research. The policy implications of these findings are then considered.     

Minimax property of stein's estimator

Stein's estimator and some other estimators of the mean of a K-variate normal distribution are known to dominate the maximum likelihood estimator under quadratic loss for K > 3, and are therefore minimax. In this paper it is shown that the minimax property of Stein's rule is preserved with respect to a generalized loss function.     

Cast in a racial mould

Women of Phokeng: Consciousness, Life Strategy, and Migrancy in South Africa 1900 ‐1983 by Belinda Bozzoli, with the assistance of Mmantho Nkotsoe, Johannesburg, Ravan Press, 1991.

Our Precious Metal: African Labour in South Africa's Gold Industry, 1970–1990 by Wilmot G. James, David Philip, James Currey &; Indiana University Press, Cape Town, London &; Bloomington,1992.

Bounds of Possibility ‐ The Legacy of Steve Biko &; Black Consciousness by N.B. Pityana, M. Ramphele, M. Mpumlwana, &; L. Wilson, (eds), Cape Town, David Philip, 1991.

Faces in the revolution: the psychological effects of violence on township youth in South Africa by Gill Straker, with Fathima Moosa, Rise Becker and Madiyoyo Nkwale. Cape Town, David Philip, 1992 and Athens, Ohio, Ohio University Press, 1992.

Lives of Courage: Women for a New South Africa by Diana E.H.Russell. New York, Basic Books, 1989.

Towards Justice? Crime and State Control in South Africa by Desiree Hansson and Dirk van Zyl Smit (eds), Cape Town, Oxford University Press, 1990.

South Africa in the Nineties by DJ van Vuuren, NE Wiehahn, NJ Rhoodie en M Wiechers (eds), HSRC Publishers, 1991.

To Live in Fear: Witchburning and Medicine Murder in Venda by A de V. Minnar, D Offringa and C Payze, HSRC, Pretoria, 1992.

The Anti‐Politics Machine: ‘Development’, Depoliticization and Bureaucratic Power by James Ferguson, Cambridge, Cambridge University Press, 1990.

Zimbabwe's Guerrilla War: Peasant Voices by Norma J. Kriger. Cambridge University Press, African Studies Series, number 70,1992.

A Passage to England ‐ Barbadian Londoners speak of home by John Western. U.C.L. Press, London, 1992.

Breaking the formal frame: Readings in South African education in the eighties by Clive Millar, Sarah‐Anne Raynham and Angela Schaffer (eds). Cape Town: Oxford University Press, 1991.

Negotiation : Theories, Strategies and Skills by Wynand Pienaar and Manie Spoelstra, Kenwyn, Juta, 1991

SUM: Selected Works by Martin Versveld. Cape Town: Carrefour Press 1991.

Projections in the Past Tense, by Kelwyn Sole. Ravan Press, 1992.     

A long way from home: On black identity in Britain

This article sets out to challenge much of the current literature on the self‐identity of blacks in British society. By looking at the long‐term historical background, the colonial heritage of cultural, political and economic oppression, a series of more subtle analyses emerges. Among the stereotypes challenged is that of the generational gap; evidence is cited to indicate a far greater common awareness and identity of aims and attitudes than previous writers have suggested. Hie conclusion examines some strategies for fighting racism within British society.     

A functional connectivity approach for modeling cross-sectional dependence with an application to the estimation of hedonic housing prices in Paris

This paper proposes a functional connectivity approach, inspired by brain imaging literature, to model cross-sectional dependence. Using a varying parameter framework, the model allows correlation patterns to arise from complex economic or social relations rather than being simply functions of economic or geographic distances between locations. It nests the conventional spatial and factor model approaches as special cases. A Bayesian Markov Chain Monte Carlo method implements this approach. A small scale Monte Carlo study is conducted to evaluate the performance of this approach in finite samples, which outperforms both a spatial model and a factor model. We apply the functional connectivity approach to estimate a hedonic housing price model for Paris using housing transactions over the period 1990–2003. It allows us to get more information about complex spatial connections and appears more suitable to capture the cross-sectional dependence than the conventional methods.     

Does product complexity matter for competition in experimental retail markets?

We describe a first experiment on whether product complexity affects competition and consumers in retail markets. We are unable to detect a significant effect of product complexity on prices, except insofar as the demand elasticity for complex products is higher. However, there is qualified evidence that complex products have the potential to induce consumers to buy more than they would otherwise. In this sense, consumer exploitability in quantities cannot be ruled out. We also find evidence for shaping effects: consumers’ preferences are shaped by past experience with prices, and firms may in principle exploit this to sell more.     

A Diamond-Stiglitz approach to the demand for self-protection

The existing research concerning the relationship between risk aversion and prudence and the demand for self-protection assumes that the loss variable follows a Bernoulli distribution, and that changes in the level of self-protection are mean preserving. The analysis here replaces these two very strong conditions with ones which are more general. When doing this, the method of analysis is also significantly modified. This modification includes representing a change in the level of self-protection using the procedure developed by Diamond and Stiglitz (Journal of Economic Theory 8:337-360, 1974) for representing a change in risk. This alternate representation allows the existing findings to be generalized considerably, and also simplifies the analysis.     

Teacher-Based Racial Discrimination: The Role of Racial Pride and Religiosity Among African American and Caribbean Black Adolescents

This study explored the extent to which private regard and religiosity beliefs serve as protective factors for school bonding among African American and Caribbean black adolescents who experience racial discrimination in school. Findings are drawn from a nationally representative sample of (n = 810) African American and (n = 360) Caribbean black adolescents (52% girls) aged 13–17 (M_age = 15, SD = 1.42) years. Results suggest that perceiving racial discrimination from teachers was associated with lower levels of school bonding for African American and Caribbean black adolescents. For African American adolescents, perceiving more racial discrimination from teachers and reporting lower private regard beliefs was associated with less school bonding. The findings for Caribbean black adolescents revealed that endorsing moderate levels of religiosity and perceiving higher rates of teacher discrimination was associated with less school bonding. The developmental significance and implications for future research are discussed.     

Sign Restrictions,Structural Vector Autoregressions,and Useful Prior Information

This paper makes the following original contributions to the literature. (i) We develop a simpler analytical characterization and numerical algorithm for Bayesian inference in structural vector autoregressions (VARs) that can be used for models that are overidentified, just‐identified, or underidentified. (ii) We analyze the asymptotic properties of Bayesian inference and show that in the underidentified case, the asymptotic posterior distribution of contemporaneous coefficients in an n‐variable VAR is confined to the set of values that orthogonalize the population variance–covariance matrix of ordinary least squares residuals, with the height of the posterior proportional to the height of the prior at any point within that set. For example, in a bivariate VAR for supply and demand identified solely by sign restrictions, if the population correlation between the VAR residuals is positive, then even if one has available an infinite sample of data, any inference about the demand elasticity is coming exclusively from the prior distribution. (iii) We provide analytical characterizations of the informative prior distributions for impulse‐response functions that are implicit in the traditional sign‐restriction approach to VARs, and we note, as a special case of result (ii), that the influence of these priors does not vanish asymptotically. (iv) We illustrate how Bayesian inference with informative priors can be both a strict generalization and an unambiguous improvement over frequentist inference in just‐identified models. (v) We propose that researchers need to explicitly acknowledge and defend the role of prior beliefs in influencing structural conclusions and we illustrate how this could be done using a simple model of the U.S. labor market.