Does testosterone mediate the trade-off between nestling begging and growth in the canary (Serinus canaria)?

Nestling birds solicit food from their parents with vigorous begging displays, involving posturing, jostling and calling. In some species, such as canaries, begging is especially costly because it causes a trade off against nestling growth. Fitness costs of begging like this are predicted by evolutionary theory because they function to resolve conflicts of interest within the family over the provision of parental investment. However, the mechanism that links these costs with nestling behaviour remains unclear. In the present study, we determine if the relationships between nestling androgen levels, nestling begging intensities and nestling growth rates are consistent with the hypothesis that testosterone is responsible for the trade-off between begging and growth. We test this idea with a correlational study, using fecal androgens as a non-invasive method for assaying nestling androgen levels. Our results show that fecal androgen levels are positively correlated with nestling begging intensity, and reveal marked family differences in each trait. Furthermore, changes in fecal androgen levels between 5 and 8 days after hatching are positively associated with changes in nestling begging intensity, and negatively associated with nestling growth during this time. Although these correlational results support our predictions, we suggest that that experimental manipulations are now required to test the direct or indirect role of testosterone in mediating the trade-off between begging and growth.

Disorganized attachment and reproductive strategies

Del Giudice provides an extension of the life history theory of attachment that incorporates emerging data suggestive of sex differences in avoidant male and preoccupied female attachment patterns emerging in middle childhood. This commentary considers the place of disorganized attachment within this theory and why male children may be more prone to disorganized attachment by drawing on Trivers’s parental investment theory.

Nest visit synchrony is high and correlates with reproductive success in the wild Zebra finch Taeniopygia guttata

Nest visit synchrony, whereby adults coordinate their visits to the nest, has been documented in several species of cooperative breeders. Visit synchrony may reduce nest predation rate or sibling competition, or instead follow from synchronisation of other behaviours, such as foraging. However, nest visit synchrony has rarely been considered in species with bi-parental care, even though it could conceivably bring similar fitness benefits to that seen in cooperative breeders. In addition, in species with bi-parental care, we might expect nest visit synchrony to reflect the quality of the pair or the overall coordination of breeding activity between partners. Here, we tested whether nest visit synchrony occurs in a classic avian model for the study of bi-parental care, the zebra finch Taeniopygia guttata. We found that in the wild, both zebra finch parents visited the nest very infrequently during nestling provisioning, with only one visit per hour, and that nest visits were highly synchronised with parents visiting the nest together on 78% of the visits. In addition, we found that nest visit synchrony was correlated with hatching rate, brood size at hatching and the number of offspring in the nest a few days prior to fledging. Our results suggest that, while more work is required to understand the benefits of nest visit synchrony in this species, considering behavioural synchrony and cooperation between mated partners may offer new insight into the study of parental investment, including in species with bi-parental care.

Using an Electronic Monitoring System to Link Offspring Provisioning and Foraging Behavior of a Wild Passerine

Although the costs of parental care are at the foundations of optimal-parental-investment theory, our understanding of the nature of the underlying costs is limited by the difficulty of measuring variation in foraging effort. We simultaneously measured parental provisioning and foraging behavior in a free-living population of Zebra Finches (Taeniopygia guttata) using an electronic monitoring system. We fitted 145 adults with a passive transponder tag and remotely recorded their visits to nest boxes and feeders continuously over a 2-month period. After validating the accuracy of this monitoring system, we studied how provisioning and foraging activities varied through time (day and breeding cycle) and influenced the benefits (food received by the offspring) and costs (interclutch interval) of parental care. The provisioning rates of wild Zebra Finches were surprisingly low, with an average of only one visit per hour throughout the day. This was significantly lower than those reported for this model species in captivity and for most other passerines in the wild. Nest visitation rate only partially explained the amount of food received by the young, with parental foraging activity, including the minimum distance covered on foraging trips, being better predictors. Parents that sustained higher foraging activity and covered more distance during the first breeding attempt took longer to renest. These results demonstrate that in some species matching foraging activity with offspring provisioning may provide a better estimate of the true investment that individuals commit to a reproductive attempt.

Parental nurturing and adverse effects of redistribution

This paper suggests that if parental nurturing is a dominating force in human capital formation then income redistribution may not promote economic growth. In particular, if, consistently with empirical evidence, parental human capital complements investment in a child’s education and yields increasing returns in the intergenerational production of human capital, income redistribution may have an adverse impact on the growth rate of average human capital. Redistribution shifts resources towards the less educationally-productive families and thus in the presence of credit markets imperfections and increasing returns, it reduces the aggregate level of investment in human capital. Moreover, if the degree of increasing returns is sufficiently large to produce sustained growth, this adverse effect on human capital formation may outweigh the conventional beneficial effects of redistribution that arises from the interaction between a production technology exhibiting diminishing returns and credit market imperfections.

The effect of low parental warmth and low monitoring on disordered eating in mid-adolescence: findings from the Australian Temperament Project

OBJECTIVE: To investigate the interactions between low parental warmth and monitoring at age 13-14 years and disordered eating attitudes and behaviours at age 15-16 years. METHOD: Data on 1300 (667 females) adolescents and their parents were drawn from The Australian Temperament Project (ATP), a 30 year (15 wave) population based longitudinal study of social-emotional development. Parent participants completed surveys on parenting practices in late childhood, and adolescent participants reported disordered eating using the drive for thinness and bulimia subscales of the Eating Disorder Inventory (EDI) and an additional body dissatisfaction scale. Interaction was examined on the additive scale by estimating super-additive risk; i.e., risk in excess of the sum of individual risks. RESULTS: For boys, neither parental warmth or monitoring, nor their interaction, was related to disordered eating. For girls, low parental warmth (alone) was associated with bulimic behaviours. In contrast, exposure to both low monitoring and warmth was associated with ∼3½-fold, ∼4-fold and ∼5-fold increases in the odds of reporting body dissatisfaction, drive for thinness and bulimia, respectively. For body dissatisfaction and drive for thinness, risk associated with joint exposure exceeded the sum of individual risks, suggesting an additive interaction between parenting styles. CONCLUSION: Further investment in family-level interventions that focus on promoting parental monitoring behaviour and a warm parent-child relationship remain important strategies for preventing a range of disordered eating behaviours in adolescents.

Vocal negotiation over parental care? Acoustic communication at the nest predicts partners' incubation share

In species with biparental care, individuals adjust their workload to that of their partner to either compensate or match its investment. Communication within a pair might be crucial for achieving this adjustment. Zebra finches, Taeniopygia guttata, form life-long monogamous pair bonds, in which partners are highly coordinated and both incubate the eggs. When relieving each other during incubation, partners perform a structured call duet at the nest. If this duet functions to coordinate incubation workload, disrupting the pair's usual nest-relief pattern by delaying the male's return to the nest should affect the structure of the duet. Using domesticated birds breeding in a large aviary, we found that delaying the male's return induced shorter duets with higher call rates. In addition, we tracked the location of individuals with a transponder at the nest and the feeder, and showed that these accelerated duets were associated with an increased haste of the partners to take turns incubating and foraging. Females also spent less time incubating during their subsequent shift, and females' time off-nest was best predicted by their mate's calling behaviour in the previous duet. Taken together, these results suggest that duets may function as 'vocal negotiation' over parental care.

The association between the investment opportunity set and corporate financing and dividend decisions: some Australian evidence

Summarizes previous research on the investment opportunity set (IOS) using price-based and investment-based proxies and variance measures; and develops hypotheses on the relationship between IOS, debt/equity ratios and dividend policies. Tests them on 1990-1998 data from listed Australian companies and explains the methodology, which builds on Gover and Gover (1993) by including more recent proxy variables. Finds no significant results from low growth firms, although some high growth firms show lower debt/equity ratios and dividends. Questions the robustness of existing IOS proxies in the Australian context and calls for further research.

Tax incentives for foreign direct investment part II : Design considerations

Part I of this article concluded that tax incentives for foreign direct investment (FDI) have become increasingly common over the past 10 years or so, especially among developing countries, and that there is substantial evidence to support the proposition that tax considerations now play an important role in many investment decisions. Countries seeking to attract FDI often feel compelled to offer tax inducements that are at least as attractive as those offered by their neighbours or competitors. Countries do so at a cost, however, and that cost may be substantial. Governments are thus placed in a dilemma - can they afford to cut taxes in order to attract investment, and can they afford not to? The second part of this article assumes that countries, and especially most developing countries, will continue to feel obliged to provide tax incentives. The aim of this part therefore is to examine ways in which those incentives can be made more effective and more efficient, thereby reducing their cost to the host country.

Tax incentives for foreign direct investment part I : Recent trends and countertrends

According to the conventional wisdom, tax incentives for investment - in particular for foreign direct investment (FDI) - are not recommended. That is the view held almost universally by theorists and by the international bodies that advise on tax matters.' Tax incentives are bad in theory and bad in practice. They are bad in theory principally because they cause distortions: investment decisions are made that would not have been made without the inducement of special tax concessions. They are bad in practice, being both ineffective and inefficient. They are ineffective in that tax considerations are only rarely a major determinant in FDI decisions; they are inefficient because their cost, in terms of tax revenue foregone, often far exceeds any benefits they may produce. Other criticisms are also frequently levelled against tax incentives for FDI - they are inequitable (since they benefit some investors but not others), they are difficult to administer and open to abuse, and they lack transparency. Thus, it is not surprising that ''the standard advice given by institutions like the World Bank and the lMF to developing countries is to refrain from offering tax incentives to foreign investors".2 The purpose of this article is not to question that advice or to challenge the conventional wisdom - except in one respect. Recent evidence does suggest that tax considerations are an increasingly important factor in investment decisions and that special tax incentives have become substantially more effective as instruments for attracting FDI than they were 10 or 20 years ago.3 The first part of this article, published here, examines some of that evidence, reviews some recent trends in national policies towards FDI, attempts to suggest why investment incentives have become more important and more effective, and looks at the pressures that are exerted on governments, especially in developing countries, to compete for FDI by offering special incentives. The second part of the article, to be published in the Bulletin next month, assumes that many countries will continue to offer tax incentives to investors regardless of the best advice, and considers how incentives might be designed in order to increase their effectiveness and efficiency.

A multi-agent framework for financial investment planning

If a company or person wants to invest a lot of money, where, when, and how should the investment go? A multi-agent based Financial Investment Planner may give some reasonable answers to the above question. Good advice is mainly based on adequate information, rich knowledge, and great
skills to use knowledge and information. To this end, this planner consists of four principal components information gathering agents that are responsible for gathering relevant information on the Internet, data mining agents that are in charge of discovering knowledge from retrieved information as well as other relevant databases, group decision making agents that can effectively use available knowledge and appropriate information to make reasonable decisions (investment advice), and a graphical user interface that interacts with users. This paper is focused on the group decision making part. The design and implementation of an agent-based hybrid intelligent system - agent-based soft computing society are detailed.

Exports, Inward Foreign Direct Investment (FDI) and Regional Economic Growth in China

The relationship between exports and economic growth is strong in developing economies. Both externality effects of exports on the non-exports sector and higher marginal productivity in the exports sector in relation to the non-exports sector play an important role in promoting exports and GDP growth. The underlying theoretical model of FEDER, 1982, is used with the data on the Chinese provinces and it is shown that the economic structure, degree of openness and policy environment have a significant role in the relationship between exports and economic growth.

Foreign Direct Investment and Regional Export Performance in China

This paper investigates the impact of foreign direct investment (FDI) on the export performance of China at the provincial level. First, it presents a theoretical discussion of the impact of FDI on foreign trade, and then an empirical study of the impact of FDI on the export performance of regions in Chin. It has been found that the impact of FDI on exports differs across three macro-regions in China. The effect is stronger in the coastal region than in the inland regions. Although FDI shows a positive and significant impact on exports from the central region, its impact on the western region is found to be insignificant.

Parental divorce during adolescence and adjustment in early adulthood

Presents a study which examined the relationship between parental divorce during adolescence and the psychosocial adjustment of young adults. Methods; Results; Discussion.

Investment opportunities and leverage: some Australian evidence on the role of board monitoring and director equity ownership

This paper tests the hypothesis that the negative relationship between investment opportunity set (IOS) and debt is moderated by board monitoring and director equity ownership. According to contracting theory, firms with high growth opportunities (high IOS) are associated with lower levels of debt as a result of the asset substitution and the under-investment problem. However, our hypotheses test the conjecture that the negative debt / IOS relationship will be moderated by the proportion of non-executive directors (NEDs) on the board and director equity ownership. NEDs provide higher monitoring which reduces management discretion while director equity ownership provides incentives for managers to maximize the value of the firm. More specifically, we expect that high growth firms with a higher proportion of non-executive directors and director equity ownership are less likely to be associated with asset substitution and under investment. Thus, the negative investment opportunity set / debt relationship will be weaker for firms with higher levels of non-executive directors and high director equity ownership. Data collected from Australian companies support both these two hypotheses. Results have significant implications for corporate finance theory.