A gendered 1993-94 Social Accounting Matrix for Bangladesh

This working paper documents the construction of a 1993-94 Social Accounting Matrix (SAM) for Bangladesh. The SAM distinguishes 10 agricultural sectors —including two different kinds of rice technology — and 19 manufacturing sectors, out of 43 sectors in total. It also differentiates between twelve socio-economic groups, allowing detailed analysis of household welfare and poverty. The SAM has ten factors of production: one type of capital, one type of land and eight different types of labor which are disaggregated by both level of education and gender. The innovative feature of the SAM is that it separates out female and male labor value-added for each educational level and in eachsector of the economy, providing a base for gender-sensitive analyses of policy changes. The SAM is estimated with a cross-entropy approach, which makes efficient use of all available data in a framework that incorporates prior information and constraints.Mathematical models. ,Households. ,Labor Gender issues. ,Rice Bangladesh. ,TMD ,

Macro policies and the food sector in Bangladesh

Trade liberalization in the early 1990s in Bangladesh has enabled the private sector to respond with market-stabilizing inflows of rice and wheat following major production shortfalls. At the same time, easing of restrictions on foreign investment, combined with substantial depreciation of the Taka, have enabled exports of the labor-intensive ready-made garment industry to expand significantly. Moreover, recently discovered natural gas resources might be exploited, creating new revenues for the country. A proper assessment of the impact of such policies and economic developments on the poor requires a comprehensive framework to analyze interactions between different sectors, and linkages between macro and micro levels. In this paper we develop a computable general equilibrium model (CGE) with special treatment of the rice and wheat sectors, and we use it to simulate the impact of (i) a decline in rice production due to floods, (ii) a cut in food aid of wheat, and (iii) increased revenues from the exploitation of natural gas resources. The results suggest that most households benefit from more liberalized rice and wheat trade, particularly after rice production shocks. Impacts of a decline in wheat food aid are relatively modest, as food aid imports are not large enough to have major macroeconomic effects. The simulations of natural gas export revenues suggest that the extent of disincentives to agriculture will depend on whether or not the resulting real exchange rate appreciation is sufficient to lower the import parity price of rice enough so that domestic prices are affected. Finally, all three simulations show that the effects of economic shocks on women's labor and female headed poor households can differ significantly from the effects on men's labor and other households.Bangladesh ,Food production ,trade liberalization ,Female labor ,TMD ,

Chance and Necessity in Evolution: Lessons from RNA

The relationship between sequences and secondary structures or shapes in RNA exhibits robust statistical properties summarized by three notions: (1) the notion of a typical shape (that among all sequences of fixed length certain shapes are realized much more frequently than others), (2) the notion of shape space covering (that all typical shapes are realized in a small neighborhood of any random sequence), and (3) the notion of a neutral network (that sequences folding into the same typical shape form networks that percolate through sequence space). Neutral networks loosen the requirements on the mutation rate for selection to remain effective. The original (genotypic) error threshold has to be reformulated in terms of a phenotypic error threshold. With regard to adaptation, neutrality has two seemingly contradictory effects: It acts as a buffer against mutations ensuring that a phenotype is preserved. Yet it is deeply enabling, because it permits evolutionary change to occur by allowing the sequence context to vary silently until a single point mutation can become phenotypically consequential. Neutrality also influences predictability of adaptive trajectories in seemingly contradictory ways. On the one hand it increases the uncertainty of their genotypic trace. At the same time neutrality structures the access from one shape to another, thereby inducing a topology among RNA shapes which permits a distinction between continuous and discontinuous shape transformations. To the extent that adaptive trajectories must undergo such transformations, their phenotypic trace becomes more predictable.Comment: 37 pages, 14 figures; 1998 CNLS conference; high quality figures at http://www.santafe.edu/~walte

St. Petersburg Paradox and Failure Probability

The St. Petersburg paradox provides a simple paradigm for systems that show sensitivity to rare events. Here, we demonstrate a physical realization of this paradox using tensile fracture, experimentally verifying for six decades of spatial and temporal data and two different materials that the fracture force depends logarithmically on the length of the fiber. The St. Petersburg model may be useful in a variety fields where failure and reliability are critical

Keck/MOSFIRE Spectroscopy of z=7-8 Galaxies: Lyα\alpha Emission from a Galaxy at z=7.66

We report the results from some of the deepest Keck/Multi-Object Spectrometer For Infra-Red Exploration data yet obtained for candidate $z \gtrsim 7$ galaxies. Our data show one significant line detection with 6.5$\sigma$ significance in our combined 10 hr of integration which is independently detected on more than one night, thus ruling out the possibility that the detection is spurious. The asymmetric line profile and non-detection in the optical bands strongly imply that the detected line is Ly$\alpha$ emission from a galaxy at $z$(Ly$\alpha)=7.6637 \pm 0.0011$, making it the fourth spectroscopically confirmed galaxy via Ly$\alpha$ at $z>7.5$. This galaxy is bright in the rest-frame ultraviolet (UV; $M_{\rm UV} \sim -21.2$) with a moderately blue UV slope ($\beta=-2.2^{+0.3}_{-0.2}$), and exhibits a rest-frame Ly$\alpha$ equivalent width of EW(Ly$\alpha$) $\sim 15.6^{+5.9}_{-3.6}$ \AA. The non-detection of the 11 other $z \sim$ 7-8 galaxies in our long 10 hr integration, reaching a median 5$\sigma$ sensitivity of 28 \AA\ in the rest-frame EW(Ly$\alpha$), implies a 1.3$\sigma$ deviation from the null hypothesis of a non-evolving distribution in the rest-frame EW(Ly$\alpha$) between $3<z<6$ and $z=$ 7-8. Our results are consistent with previous studies finding a decline in Ly$\alpha$ emission at $z>6.5$, which may signal the evolving neutral fraction in the intergalactic medium at the end of the reionization epoch, although our weak evidence suggests the need for a larger statistical sample to allow for a more robust conclusion.Comment: 10 pages, 4 figures, ApJ, in pres

Electrical Analogs of Atomic Radiative Decay Processes

This is the published version, available from the publisher at http://dx.doi.org/10.1119/1.10986.Simple electrical circuits are analyzed, and the results show that for high frequencies they have frequency and time responses identical to the spontaneous radiative decays of atoms. As an illustration of the analogy a two-circuit electrical system is compared with a two-level atom. The comparison leads to the identification of electrical analogs for quantum­ mechanical quantities. It is also shown that the responses of an appropriate electrical circuit can be compared with the decay characteristics of coupled three-level atomic systems

Ground‐State Wavefunctions and Energies for the Helium Isoelectronic Series through Z = 10

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69577/2/JCPSA6-47-8-3077-1.pd

One‐ and Two‐Center Expansions of the Breit‐Pauli Hamiltonian

The orbit‐orbit, spin‐spin, and spin‐orbit Hamiltonians of the Breit‐Pauli approximation are expressed in terms of irreducible tensors. One‐ and two‐center expansions are given in a form in which the coordinate variables of the interacting particles are separated. In the one‐center expansions of the orbit‐orbit and spin‐orbit Hamiltonians the use of the gradient formula reduces some of the infinite sums to finite ones. Two‐center expansions are discussed in detail for the case of nonoverlapping charge distributions. The angular parts of the matrix elements of these Hamiltonians are evaluated for product wavefunctions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70736/2/JMAPAQ-9-9-1357-1.pd