The Fatou property of block spaces

Around thirty years ago, block spaces, which are the predual of Morrey spaces, had been considered. However, it seems that there is no proof that block spaces satisfy the Fatou property. In this paper the Fatou property for block spaces is verified and the predual of block spaces is characterized

Bouncing gel balls: impact of soft gels onto rigid surface

After thrown onto a solid substrate, very soft spherical gels bounce repeatedly. Separate rheological measurements suggest that these balls can be treated as nearly elastic. The Hertz contact deformation expected in the static (elastic) limit was observed only at very small impact velocities. For larger velocities, the gel ball deformed into flattened forms like a pancake. We measured the size of the gel balls at the maximal deformation and the contact time as a function of velocities for the samples different in the original spherical radius and the Young modulus. The experimental results revealed a number of scaling relations. To interpret these relations, we developed scaling arguments to propose a physical picture.Comment: 7 pages, 4 figures (minor revisions, To appear in Europhys. Lett.

Principal Component Analysis for Functional Data

In functional principal component analysis (PCA), we treat the data that consist of functions not of vectors (Ramsay and Silverman, 1997). It is an attractive methodology, because we often meet the cases where we wish to apply PCA to such data. But, to make this method widely useful, it is desirable to study advantages and disadvantages in actual applications. As alternatives to functional PCA, we may consider multivariate PCA applied to 1) original observation data, 2) sampled functional data with appropriate intervals, and 3) coefficients of basis function expansion. Theoretical and numerical comparison is made among ordinary functional PCA, penalized functional PCA and the above three multivariate PCA

Agglomeration economies in the formal and informal sectors : a Bayesian spatial approach

This paper examines whether localized clusters of similar industries produce agglomeration economies in the formal and informal sectors. We develop a Bayesian method to estimate a spatial autoregressive model with an endogenous independent variable. We use establishment-level census data that cover both formal registered and informal unregistered establishments in Cambodia. We find that the density of local employment has a significantly positive effect on productivity in the informal sector, but little effect in the formal sector. For manufacturing, a doubling of employment density increases productivity in the informal sector by 9% through local linkages and by 17% through spatial multiplier linkages, leading to a 26% increase in total. A spatial network magnifies the local impact of agglomeration economies in the informal sector

Spatial spillovers from FDI agglomeration : evidence from the Yangtze River Delta in China

Foreign firms have clustered together in the Yangtze River Delta, and their impact on domestic firms is an important policy issue. This paper studies the spatial effect of FDI agglomeration on the regional productivity of domestic firms, using Chinese firm-level data. To identify local FDI spillovers, we estimate the causal impact of foreign firms on domestic firms in the same county and similar industries. We then estimate a spatial-autoregressive model to examine spatial spillovers from FDI clusters to other domestic firms in distant counties. Our results show that FDI agglomeration generates positive spillovers for domestic firms, which are stronger in nearby areas than in distant areas

Agglomeration and firm-level productivity : a Bayesian spatial approach

This paper estimates the impact of industrial agglomeration on firm-level productivity in Chinese manufacturing sectors. To account for spatial autocorrelation across regions, we formulate a hierarchical spatial model at the firm level and develop a Bayesian estimation algorithm. A Bayesian instrumental-variables approach is used to address endogeneity bias of agglomeration. Robust to these potential biases, we find that agglomeration of the same industry (i.e. localization) has a productivity-boosting effect, but agglomeration of urban population (i.e. urbanization) has no such effects. Additionally, the localization effects increase with educational levels of employees and the share of intermediate inputs in gross output. These results may suggest that agglomeration externalities occur through knowledge spillovers and input sharing among firms producing similar manufactures

Agglomeration effects of informal sector: evidence from Cambodia

The presence of a large informal sector in developing economies poses the question of whether informal activity produces agglomeration externalities. This paper uses data on all the nonfarm establishments and enterprises in Cambodia to estimate the impact of informal agglomeration on the regional economic performance of formal and informal firms. We develop a Bayesian approach for a spatial autoregressive model with an endogenous explanatory variable to address endogeneity and spatial dependence. We find a significantly positive effect of informal agglomeration, where informal firms gain more strongly than formal firms. Calculating the spatial marginal effects of increased agglomeration, we demonstrate that more accessible regions are more likely than less accessible regions to benefit strongly from informal agglomeration