Loans and Leaving: Migration and the Expansion of Microcredit in Cambodia

Over the last decade, the expansion of microfinance institutions (MFIs) has dramatically shifted the availability of credit across the developing world. This recent development provides an opportunity to examine the relationship between household labor migration and access to and use of formal credit. Both theories of migration and the expectations of formal credit providers have suggested that labor migration and credit are substitute solutions to the demand for capital in the developing world, with the implication that greater access to formal financial services may stem migration out of rural places. Using household survey data from Cambodia, an MFI-saturated country, we find that households using formal credit and households with greater access to formal credit are more likely to have labor migrants than households without access. This association persists across size of loan, purpose of loan, remittances behavior, and for domestic migrations. These findings complicate our understanding of the relationship between credit and migration, and call for a greater recognition of the importance of context in framing migration behavior

Three-dimensional local density of states in a finite two-dimensional photonic crystal composed of cylinders

The three-dimensional local density of states (LDOS), which determines the radiation dynamics of a point source, is presented here for a finite two-dimensional photonic crystal as a function of space and frequency. The LDOS is obtained from the dyadic Green’s function, which is calculated exactly using the multipole method. Maximum suppression in the LDOS occurs at the high frequency edge of the complete two-dimensional band gap and varies smoothly about this frequency. Macroporous silicon is shown to suppress the LDOS by one order of magnitude at the center of its air pores. © 2003 The American Physical Society

Long wavelength behavior of the fundamental mode in microstructured optical fibers

Using a novel computational method, the fundamental mode in index-guided microstructured optical fibers with genuinely infinite cladding is studied. It is shown that this mode has no cut-off, although its area grows rapidly when the wavelength crosses a transition region. The results are compared with those for w-fibers, for which qualitatively similar results are obtained. © 2005 Optical Society of America

From Multipole Methods to Photonic Crystal Device modeling

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