Computer program for interplanetary conic patching

Computer program enables study of one-way transfers, single and double planet flybys, single and double planet stopovers, or mixed flyby and stopover trajectories. In each operation it first computes the heliocentric conic which connects the centers of the launch and target planets and requires a given trip time

Veterans’ Benefits: Pension Benefit Programs

[Excerpt] The Department of Veterans Affairs (VA) administers pension programs for certain low-income veterans and their surviving spouses and dependent children. This report discusses the Improved Disability Pension, which makes payments to certain low-income veterans, and the Improved Death Pension, which makes payments to certain low-income surviving spouses and dependent children of deceased veterans. To qualify for either program, individuals must have become eligible for payments on or after January 1, 1979. Both pension programs were created by P.L. 95-588, the Veterans and Survivors Pension Improvement Act of 1978. In addition, this report discusses a special pension program for Medal of Honor recipients. This report does not discuss several other pension programs that are administered by the VA, such as the Old Law Disability Pension and the Section 306 Disability Pension, which make payments to low-income veterans, and the Old Law Death Pension and the Section 306 Death Pension, which make payments to low-income surviving spouses and dependent children of veterans; these programs apply only to veterans and their survivors who became entitled to such benefits before 1979. This report also does not discuss pension programs for veterans of specific periods of war before World War I, such as the Civil War, the Indian Wars, and the Spanish-American War. Finally, this report does not address the military retirement system. For information on that system, see CRS Report RL34751, Military Retirement: Background and Recent Developments, by Kristy N. Kamarck

Could early warning systems have helped to predict the sub prime crisis?

One of the features of the sub-prime crisis, that began in August 2007, was its unexpected nature. It came as a surprise not only to most financial market participants but also in some degree to the policy community. In this context, we seek to assess whether early warning systems based on the logit and binomial tree approaches on the UK and US economies could have helped to warn about the crisis. We also consider a “check list approach” of indicators based on history. Although not all of the complementary approaches are successful, we contend that our work suggests that a broadening of approaches of macroprudential analysis is appropriate

Pure Numbers Effects, Market Power, and Tacit Collusion in Posted Offer Markets

This paper studies the effects of seller concentration and static market power on tacit collusion in extensively repeated laboratory posted-offer markets. Contrary to the implications of some earlier research, we find that tacit collusion does not become pervasive with extensive repetition. In a ‘strong no power’ design persistently competitive outcomes are observed in markets with three or four sellers. Even duopolies are frequently competitive in this design. Unilateral market power raises prices, as predicted. However, static Nash predictions fail to organize outcomes across power treatments, because tacit collusion moves inversely with concentration. Excess capacity appears to explain observed tacit collusion levels.experiments, market concentration, market power

Rebate Subsidies, Matching Subsidies and Isolation Effects

In a series of recent experiments (Davis, Millner and Reilly, 2005, Eckel and Grossman, 2003, 2005a-c, 2006), matching subsidies generate significantly higher charity receipts than do theoretically equivalent rebate subsidies. This paper reports a laboratory experiment conducted to examine whether the higher receipts are attributable to a relative preference for matching subsidies or to an ‘isolation effect’ (McCaffery and Baron, 2003, 2006). Some potential policy implications of isolation effects on charitable contributions are also considered.experiments, charitable contributions, methodology

Error analysis of penetrator impacts on bodies without atmospheres

Penetrators are missile shaped objects designed to implant electronic instrumentation in various of surface materials with a nominal impact speed around 150 m/sec. An interest in the application of this concept to in situ subsurface studies of extra terrestrial bodies and planetary satellites exists. Since many of these objects do not have atmospheres, the feasibility of successfully guiding penetrators to the required near-zero angle-of-attack impact conditions in the absence of an atmosphere was analyzed. Two potential targets were included, i.e., the moon and Mercury and several different penetrator deployment modes were involved. Impact errors arising from open-loop and closed-loop deployment control systems were given particular attention. Successful penetrator implacement requires: (1) that the impact speed be controlled, nominally to 150 m/sec, (2) that the angle of attack be in range 0 deg - 11 deg at impact, and (3) that the impact flight path angle be with 15 deg of vertical