L models and multiple regressions designs

Given an orthogonal model

${{\bf \lambda}}=\sum_{i=1}^m{{{\bf X}}_i}{\boldsymbol{\alpha}}_i$

an L model

${{\bf y}}={\bf L}\left(\sum_{i=1}^m{{{\bf X}}_i}{\boldsymbol{\alpha}}_i\right)+{\bf e}$

is obtained, and the only restriction is the linear independency of the column vectors of matrix L. Special cases of the L models correspond to blockwise diagonal matrices L = D(L ₁, . . . , L _c ). In multiple regression designs this matrix will be of the form

${\bf L}={\bf D}(\check{{\bf X}}_1,\ldots,\check{{\bf X}}_{c})$

with \({\check{{\bf X}}_j, j=1,\ldots,c}\) the model matrices of the individual regressions, while the original model will have fixed effects. In this way, we overcome the usual restriction of requiring all regressions to have the same model matrix.

     

Differences in fish harvest,fishing effort,and angling guard activities between urban and natural fishing grounds

Recreational fishing is a very popular outdoor leisure activity. Assessing differences in basic metrics in recreational fishing on different types of fishing grounds is very important for effective fisheries management. This study aimed to discover how basic metrics in recreational fishing (harvest, fishing effort, angling guard activities) differ between urban fishing grounds (located in a densely populated city) and natural fishing grounds (located in the countryside). Data were obtained from individual angling logbooks collected by the Czech Fishing Union on the River Elbe and the River Vltava (Prague and Central Bohemia, Czechia, Central Europe). Study shows that urban and natural fishing grounds showed significant differences in basic metrics in recreational fishing. Urban fishing grounds displayed higher fish harvest in general and higher dominance of intensively stocked fish species in catches of anglers (mainly common carp Cyprinus carpio). High harvest rates of common carp can be mostly explained by intensive fish stocking. The only fish species that showed higher harvest on natural fishing grounds were large-growing piscivorous fish with high ecological demands. However, anglers were harvesting larger fish (average body weight) on natural fishing grounds. In addition, fishing effort was similar on both types of fishing grounds. Inversely, angling guards were more active on natural fishing grounds. In conclusion, differences in basic fisheries metrics between urban and natural fishing grounds seem to be partially driven by intensive fish stocking.

     

Trends in Spouses’ Shared Time in the United States, 1965–2012

Despite major demographic changes over the past 50 years and strong evidence that time spent with a spouse is important for marriages, we know very little about how time with a spouse has changed—or not—in the United States. Using time diary data from 1965–2012, we examine trends in couples’ shared time in the United States during a period of major changes in American marriages and families. We find that couples without children spent more total time together and time alone together in 2012 than they did in 1965, with total time and time alone together both peaking in 1975. For parents, time spent together increased between 1965 and 2012, most dramatically for time spent with a spouse and children. Decomposition analyses show that changes in behavior rather than changing demographics explain these trends, and we find that the increases in couples’ shared time are primarily concentrated in leisure activities.     

Transnational land investment web: land grabs,TNCs, and the challenge of global governance

ABSTRACT

Despite international media’s waning attention, research and political debates on global land grabbing have not subsided. We argue the importance of understanding the ‘transnational land investment web’ of corporate and state actors and institutions, which are not always immediately visible. Focusing on transnational corporations (TNCs) based in the European Union (EU), we examine five sets of actors and institutional spheres through which these actors are able to grab lands beyond Europe. It is crucial to understand these not as individual sets of actors or institutions, but as interconnected sets, comprising a web. These are EU-based: (1) Private companies using regular institutional platforms; (2) Finance capital companies; (3) Public–private partnerships; (4) Development Finance Institutions; and (5) Companies using EU policies to gain control of land through the supply chain. One implication of this complex web is that democratic governance in the context of land grabs becomes an even more daunting challenge.     

TRUST,RECIPROCITY, AND RULES

Many economic interactions rely on trust and trust violations can have serious economic consequences. Simple minimum standard rules are attractive because they prevent egregious trust violations. However, they may undermine more trusting and reciprocal (trustworthy) behavior that otherwise would have occurred, leading to worse outcomes. In an experimental trust game, we test the efficacy of exogenously imposed minimum standard rules. Rules damage trust and reciprocity, reducing economic welfare. While sufficiently restrictive rules restore welfare, trust and reciprocity never return. Results indicate that participants are concerned about payoffs while also using the game to learn about trust and trustworthiness of others. (JEL C72, C90, D63, D64, L51)     

The balance of planting and mortality in a street tree population

Street trees have aesthetic, environmental, human health, and economic benefits in urban ecosystems. Street tree populations are constructed by cycles of planting, growth, death, removal and replacement. The goals of this study were to understand how tree mortality and planting rates affect net population growth, evaluate the shape of the mortality curve, and assess selected risk factors for survival. We monitored a street tree population in West Oakland, CA for 5 years after an initial inventory (2006). We adapted the classic demographic balancing equation to quantify annual inputs and outputs to the system, tracking pools of live and standing dead trees. There was a 17.2 % net increase in live tree counts during the study period (995 in 2006, 1166 in 2011), with population growth observed each year. Of the live trees in 2006, 822 survived to 2011, for an annual mortality rate of 3.7 %. However, population growth was constrained by high mortality of young/small trees. Annual mortality was highest for small trees, and lower for mid-size and large trees; this represents a Type III mortality curve. We used multivariate logistic regression to evaluate the relationship between 2011 survival outcomes and inventory data from 2006. In the final model, significant associations were found for size class, foliage condition, planting location, and a multiplicative interaction term for size and foliage condition. Street tree populations are complex cultivated systems whose dynamics can be understood by a combination of longitudinal data and demographic analysis. Urban forest monitoring is important to understand the impact of tree planting programs.     

CULTURAL STUDIES IN GERMANY REVISITED

By drawing upon the insights of the Bakhtin Circle, this paper explores the extent to which the public sphere can open up possibilities for resistance to dominant social relations through ‘traces of meaning’. The author wishes to show how a public space for execution in seventeenth and eighteenth century London opened up a place at different levels of abstraction for a popular plebeian public sphere to flourish. When this public sphere disappeared in 1783, it is shown how its traces of meaning still survived in popular culture. These traces of meaning were re-combined through a royal crisis by more political labouring movements in the early nineteenth century that, in the main, unintentionally re-accentuated the same seventeenth- and eighteenth century-public space in London. By exploring the changing form of this public sphere it is shown how a dominant discourse changes over time and how this dominant discourse can be rendered in the words of Mikhail Bakhtin as ‘heteroglossic’ and refracted into modes of public resistance in specific spaces. To demonstrate this, the ideological form of the public sphere in early nineteenth century Britain is outlined and is then shown how it became refracted within the royal scandal which, in turn, came to be refracted within a specific space in London.