Financing patterns around the world : the role of institutions

Using a firm-level survey database covering 48 countries, the authors investigate whether differences in financial and legal development affect the way firms finance their investments. The results indicate that external financing of investments is not a function of institutions, although the form of external finance is. The authors identify two explanations for this. First, legal and financial institutions affect different types of external finance in offsetting ways. Second, firm size is an important determinant of whether firms can have access to different types of external finance. Larger firms with financing needs are more likely touse external finance compared with small firms. The results also indicate that these firms are more likely to use external finance in more developed financial systems, particularly debt and equity finance. The authors also find evidence consistent with the pecking order theory in financially developed countries, particularly for large firms.Payment Systems&Infrastructure,Banks&Banking Reform,Financial Intermediation,International Terrorism&Counterterrorism,Decentralization,Financial Intermediation,Housing Finance,Banks&Banking Reform,National Governance,Economic Theory&Research

Rhythmic firing patterns in SCN: The role of circuit interactions

The suprachiasmatic nucleus (SCN) is believed to contain the main generator of circadian rhythmicity in mammals. In order to obtain further functional details of this, electrophysiological extracellular measurements in vitro were made. By means of an interspike interval distribution analysis, it is shown that there is a novel kind of neuronal firing pattern: the harmonic pattern. From these observations, we have developed a theoretical model based on possible filtering processes occurring during synaptic transmission. The model suffices to infer that regular ultradian oscillators could be an emergent property of circuit interactions of cells in the suprachiasmatic nucleus

The role of spatial averaging in the precision of gene expression patterns

During embryonic development, differentiating cells respond via gene expression to positional cues from morphogen gradients. While gene expression is often highly erratic, embryonic development is precise. We show by theory and simulations that diffusion of the expressed protein can enhance the precision of its expression domain. While diffusion lessens the sharpness of the expression boundary, it also reduces super-Poissonian noise by washing out bursts of gene expression. Balancing these effects yields an optimal diffusion constant maximizing the precision of the expression domain.Comment: 5 pages, 4 EPS figure

Patterns of industrial development revisted : the role of finance

The authors reexamine the role of financial market development in the intersectoral allocation of resources. First, they characterize the assumptions underlying previous work in this area, in particular, that of Rajan and Zingales (1998). The authors argue that Rajan and Zingales (1998) implicitly test whether financial intermediaries allow firms to better respond to global shocks to growth opportunities. Second, the authors propose a more efficient alternative test of this hypothesis using statistical techniques developed in the social networks literature. Specifically, they find that countries have more highly correlated growth rates across sectors when they have well-developed financial markets, suggesting that financial markets play an important role in allowing firms to take advantage of global growth opportunities. These results are particularly strong when financial development takes into account both the level and composition of financial development: private banking appears to play a particularly important role in resource allocation. The authors'technique allows them to further distinguish between the"growth opportunities"hypothesis stated above and the alternative"finance and external dependence"hypothesis, which implies that countries with similar levels of financial development should specialize in similar sectors. They do not find evidence to support this alternative view of finance and development.Payment Systems&Infrastructure,Economic Theory&Research,Public Health Promotion,Health Monitoring&Evaluation,Economic Conditions and Volatility,Achieving Shared Growth,Governance Indicators,Economic Growth,Health Monitoring&Evaluation,Economic Conditions and Volatility

Self-selection patterns in Mexico-U.S. migration: the role of migration networks

This paper examines the role of migration networks in determining self-selection patterns of Mexico-U.S. migration. We first present a simple theoretical framework showing how such networks impact on migration incentives at different education levels and, consequently, how they are likely to affect the expected skill composition of migration. Using survey data from Mexico, we then show that the probability of migration is increasing with education in communities with low migrant networks, but decreasing with education in communities with high migrant networks. This is consistent with positive self-selection of migrants being driven by high migration costs, as advocated by Chiquiar and Hanson (2005), and with negative self-selection of migrants being driven by lower returns to education in the U.S. than in Mexico, as advocated by Borjas (1987)

Consumption patterns and the black middle class: The role of assets

Black consumption patterns differ from those of whites, even when considering income levels and household size. This applies particularly to the black middle class, the subject of intense public interest. This paper postulates that this difference results not from cultural differences in taste for middle class goods, but from an asset deficit experienced by blacks. We test this hypothesis using regression analysis based on the 2000 Income and Expenditure Survey. Once assets are considered, consumption of middle class goods by blacks even exceeds those of whites. One would then expect blacks to exhibit, compared to whites, (i) an asset deficit, (ii) an asset preference in purchases (to reduce the deficit), and (iii) a lag in consuming other middle class goods (if the asset deficit is not considered). Descriptive evidence, mainly graphical, from the All Media and Products Survey (AMPS) of 2004 provides support for the main hypothesis. This implies that, for black accruals to the middle class, a stage of asset accumulation would precede a stage of middle class consumption. But once assets have been acquired, the shift in consumption may be quite rapid. There may therefore remain two distinct groups of black middle class consumers: The established middle class (currently still quite small), who have accumulated assets and whose consumption patterns therefore would resemble those of whites; and the new middle class, who may prefer spending to acquire assets.Market definition, Delineation, Quantitative, Stationarity tests, Prices, Geographic, SSNIP, Hypothetical monopolist, Competition, Unit root, Price ratio, Antitrust

Learning functional object categories from a relational spatio-temporal representation

Abstract. We propose a framework that learns functional objectcategories from spatio-temporal data sets such as those abstracted from video. The data is represented as one activity graph that encodes qualitative spatio-temporal patterns of interaction between objects. Event classes are induced by statistical generalization, the instances of which encode similar patterns of spatio-temporal relationships between objects. Equivalence classes of objects are discovered on the basis of their similar role in multiple event instantiations. Objects are represented in a multidimensional space that captures their role in all the events. Unsupervised learning in this space results in functional object-categories. Experiments in the domain of food preparation suggest that our techniques represent a significant step in unsupervised learning of functional object categories from spatio-temporal patterns of object interaction.

A Semantic-based framework for discovering business process patterns

Patterns currently play an important role in modern information systems (IS) development and their use has mainly been restricted to the design and implementation phases of the development lifecycle. Given the increasing significance of business modeling in IS development, patterns have the potential of providing a viable solution for promoting reusability of recurrent generalized models in the very early stages of development. This paper focuses on business process patterns and proposes an initial framework for the discovery and reuse of business process patterns within the IS development lifecycle. The framework synthesizes the idea from the domain engineering literature and proposes the use of semantics to drive both the discovery of patterns as well as their reuse