FARM PROGRAMS AND LAND VALUES IN MOUNTAIN STATES: ALTERNATIVE PANEL ESTIMATORS

Relative proportion of agricultural land values generated by farm program payments, farm returns, and non-farm activity in the mountain region and the U.S are estimated for the period 1939 to 2005. Results suggest the contribution of farm program payments to agricultural land values in the mountain region and the U.S. is quite similar and robust across the four alternative panel estimators for the period, 1939-2005. The contribution of the farm returns to value of land is lower in the mountain region compared to the U.S. The contribution of non-farm activity to the land values is higher for the U.S. compared to the mountain region. The relationship between farm program payments and farm returns are positive in mountain region and negative for U.S.Mountain region and U.S., Agriculture land values, Farm program payments, Farm returns, Non-farm activity, Alternative Panel Estimators, Historical data, 1939-2005, Agricultural and Food Policy, Land Economics/Use,

Attochirp-free High-order Harmonic Generation

A method is proposed for arbitrarily engineering the high-order harmonic generation phase achieved by shaping a laser pulse and employing xuv light or x rays for ionization. This renders the production of bandwidth-limited attosecond pulses possible while avoiding the use of filters for chirp compensation. By adding the first 8 Fourier components to a sinusoidal field of $10^{16}$W/cm$^2$, the bandwidth-limited emission of 8 as is shown to be possible from a Li$^{2+}$ gas. The scheme is extendable to the zs-scale

Perfect equilibrium in a model of competitive arms accumulation

Economics

Higher order moments of bilinear time series processes with symmetrically distributed errors

Statistical Methods

A LOFAR search for steep-spectrum pulsars in Supernova Remnants and Pulsar Wind Nebulae

Pinpointing a pulsar in its parent supernova remnant (SNR) or resulting pulsar wind nebula (PWN) is key for understanding its formation history, and the pulsar wind mechanism. Yet, only about half the SNRs and PWNe appear associated with a pulsar. We aim to find the pulsars in a sample of eight known and new SNRs and PWNe. Using the LOFAR radio telescope at 150 MHz, each source was observed for 3 hours. We covered the entire remnants where needed, by employing many tied-array beams to tile out even the largest objects. For objects with a confirmed point source or PWN we constrained our search to those lines of sight. We identify a promising radio pulsar candidate towards PWN G141.2+5.0. The candidate, PSR J0337+61, has a period of 94 ms and a DM of 226 pc cm$^{-3}$. We re-observed the source twice with increased sensitivities of 30% and 50% but did not re-detect it. It thus remains unconfirmed. For our other sources we obtain very stringent upper limits of 0.8-3.1 mJy at 150 MHz. Generally we can rule out that the pulsars travelled out of the remnant. From these strict limits we conclude our non-detections towards point-sources and PWNe are the result of beaming and propagation effects. Some of the remaining SNRs should host a black hole rather than a neutron star.Comment: 11 pages, 3 figures, Accepted for publication in Astronomy & Astrophysic

The Displacement Effect of Public Pensions on the Accumulation of Financial Assets

The generosity of public pensions may depress private savings and provide incentives to retire early. While there is plenty of evidence supporting the latter effect, there remains considerable controversy as whether or not public pensions crowd out private savings. This paper uses international micro-datasets collected over recent years to investigate whether public pensions displace private savings. The identification strategy relies on differences in the progressivity or non-linearity of pension formulas across countries. We also make use of large heterogeneity in earnings across education group and country. The evidence we present is consistent with previous studies using cross-sectional and time-series variation in savings and pensions. We estimate that an extra dollar of pension wealth depresses accumulated financial assets at the time of retirement by 23 to 44 cents and that an extra ten thousand dollars in pension wealth reduces the average retirement age by roughly 1 month.