Agriculture's decline in Indonesia : supply or demand determined

Agriculture's share in an economy invariably declines as per capita income rises and as the economy develops. The literature on its causes has focused on the relative price effects arising from demand factors--especially Engel's Law (that the proportion of income spent on food declines as incomes rise)--rather than on such supply-side influences as changes in relative factor endowments and different rates of technical change. Engel's Law is convincing at the global level but it does not explain why agriculture's share should decline sharply in small open economies that experience rapid economic growth. A simple structural model of the transformation of the Indonesian economy, applying the Error Correction Mechanism to capture the dynamics resulting from disequilibria and costs of adjustment is developed. The authors develop an econometric model of the economy's supply side so they can explain agriculture's decline by the three theoretical factors: relative price changes, technical change, and factor accumulation. Based on the model's results, the authors conclude that the decline in the relative price of agricultural output contributed relatively little to the decline in agriculture's share. Technical change actually had a positive effect on agriculture's share, retarding the pressures for a decline in its share over time. By far the most important influence appears to have been the rapid accumulation of capital relative to labor over the period studied (1960-87).Economic Theory&Research,Environmental Economics&Policies,Agricultural Knowledge&Information Systems,Economic Growth,Inequality

Precessing supermassive black hole binaries and dark energy measurements with LISA

Spin induced precessional modulations of gravitational wave signals from supermassive black hole binaries can improve the estimation of luminosity distance to the source by space based gravitational wave missions like the Laser Interferometer Space Antenna (LISA). We study how this impacts the ablity of LISA to do cosmology, specifically, to measure the dark energy equation of state (EOS) parameter $w$. Using the $\Lambda$CDM model of cosmology, we show that observations of precessing binaries by LISA, combined with a redshift measurement, can improve the determination of $w$ up to an order of magnitude with respect to the non precessing case depending on the masses, mass ratio and the redshift.Comment: 4 pages, 4 figures, version accepted to PR

Cerenkov's Effect and Neutrino Oscillations in Loop Quantum Gravity

Bounds on the scale parameter {\cal L} arising in loop quantum gravity theory are derived in the framework of Cerenkov's effect and neutrino oscillations. Assuming that {\cal L} is an universal constant, we infer {\cal L}> 10^{-18}eV^{-1}, a bound compatible with ones inferred in different physical context.Comment: 6 pages, no figures, in print on MPL

Getting Beneath the Veil of Effective Schools: Evidence from New York City

Charter schools were developed, in part, to serve as an R&D engine for traditional public schools, resulting in a wide variety of school strategies and outcomes. In this paper, we collect unparalleled data on the inner-workings of 35 charter schools and correlate these data with credible estimates of each school's effectiveness. We find that traditionally collected input measures -- class size, per pupil expenditure, the fraction of teachers with no certification, and the fraction of teachers with an advanced degree -- are not correlated with school effectiveness. In stark contrast, we show that an index of five policies suggested by over forty years of qualitative research -- frequent teacher feedback, the use of data to guide instruction, high-dosage tutoring, increased instructional time, and high expectations -- explains approximately 50 percent of the variation in school effectiveness. Our results are robust to controls for three alternative theories of schooling: a model emphasizing the provision of wrap-around services, a model focused on teacher selection and retention, and the "No Excuses'' model of education. We conclude by showing that our index provides similar results in a separate sample of charter schools.

Probing the Brans-Dicke Gravitational Field by Cerenkov Radiation

The possibility that a charged particle propagating in a gravitational field described by Brans-Dicke theory of gravity could emit Cerenkov radiation is explored. This process is kinematically allowed depending on parameters occurring in the theory. The Cerenkov effect disappears as the BD parameter omega tends to inftinity, i.e. in the limit in which the Einstein theory is recovered, giving a signature to probe the validity of the Brans-Dicke theory.Comment: 8 pages, no figure