Multiplex electric discharge gas laser system

A multiple pulse electric discharge gas laser system is described in which a plurality of pulsed electric discharge gas lasers are supported in a common housing. Each laser is supplied with excitation pulses from a separate power supply. A controller, which may be a microprocessor, is connected to each power supply for controlling the application of excitation pulses to each laser so that the lasers can be fired simultaneously or in any desired sequence. The output light beams from the individual lasers may be combined or utilized independently, depending on the desired application. The individual lasers may include multiple pairs of discharge electrodes with a separate power supply connected across each electrode pair so that multiple light output beams can be generated from a single laser tube and combined or utilized separately

Contingent Valuation, Hypothetical Bias, and Experimental Economics

Although the contingent valuation method has been widely used to value a diverse array of nonmarket environmental and natural resource commodities, recent empirical evidence suggests it may not accurately estimate real economic values. The hypothetical nature of environmental valuation surveys typically results in responses that are significantly greater than actual payments. Economists have had mixed success in developing techniques designed to control for this "hypothetical bias." This paper highlights the role of experimental economics in addressing hypothetical bias, and identifies a gap in the existing literature by focusing on the underlying causes of this bias. Most of the calibration techniques used today lack a theoretical justification, and therefore these procedures need to be used with caution. We argue that future experimental research should investigate the reasons hypothetical bias persists. A better understanding of the causes should enhance the effectiveness of calibration techniques.Environmental Economics and Policy,

New Methods for Estimating Labor Supply Functions: A Survey

This paper surveys new methods for estimatifg labor supply functions. A unified framework of analysis is presented. All recent models of labor supply are special cases of a general index function model developed for the analysis o dummy endogenous variables.

An end to too big to let fail? The Dodd-Frank Act's orderly liquidation authority

One of the changes introduced by the sweeping new financial market legislation of the Dodd–Frank Act is the provision of a formal process for liquidating large financial firms—something that would have been useful in 2008, when troubles at Lehman Brothers, AIG, and Merrill Lynch threatened to damage the entire U.S. financial system. While it may not be the end of the too-big-to-fail problem, the orderly liquidation authority is an important new tool in the regulatory toolkit. It will enable regulators to safely close and wind up the affairs of those distressed financial firms whose failure could destabilize the financial system.Bank failures ; Financial Regulatory Reform (Dodd-Frank Act)

A new perspective on the relation between dark energy perturbations and the late-time ISW effect

The effect of quintessence perturbations on the ISW effect is studied for a mixed dynamical scalar field dark energy (DDE) and pressureless perfect fluid dark matter. A new and general methodology is developed to track the growth of the perturbations, which uses only the equation of state (EoS) parameter $w_{\rm DDE} (z) \equiv p_{\rm DDE}/\rho_{\rm DDE}$ of the scalar field DDE, and the initial values of the the relative entropy perturbation (between the matter and DDE) and the intrinsic entropy perturbation of the scalar field DDE as inputs. We also derive a relation between the rest frame sound speed $\hat{c}_{s,{\rm DDE}}^2$ of an arbitrary DDE component and its EoS $w_{\rm DDE} (z)$. We show that the ISW signal differs from that expected in a $\Lambda$CDM cosmology by as much as +20% to -80% for parameterizations of $w_{\rm DDE}$ consistent with SNIa data, and about $\pm$ 20% for parameterizations of $w_{\rm DDE}$ consistent with SNIa+CMB+BAO data, at 95% confidence. Our results indicate that, at least in principle, the ISW effect can be used to phenomenologically distinguish a cosmological constant from DDE.Comment: Accepted for publication at PR

Tax Reform and Automatic Stabilization

A fundamental property of a progressive income tax is that it provides implicit collective insurance against idiosyncratic shocks to income by dampening the variability of disposable income and consumption. The Economic Recovery Tax Act of 1981 (ERTA) and the Tax Reform Act of 1986 (TRA86) greatly reduced the number of marginal tax brackets and the maximum marginal rate, which limits the ability of households to stabilize consumption in the face of transitory fluctuations in taxable income. We examine the effect of the federal income tax reforms of the 1980s on the associated degree of automatic stabilization of consumption. The empirical framework derives from the consumption insurance literature where the ideal outcome is spatially equal changes in households' marginal utilities of consumption. Because evidence for U.S. households rejects complete consumption insurance we begin with a model of partial consumption insurance, which we use to identify how the degree of partial insurance has changed since ERTA and TRA86. Our data come from interview years 1980-1991 in the Panel Study of Income Dynamics. Although in some cases the tax reforms of the 1980s actually increased the automatic stabilization inherent in a progressive income tax (especially when the Social Security payroll tax and the Earned Income Tax Credit are included), our overall outcome is that ERTA and TRA86 reduced consumption stability by about 50 percent. More recent tax reforms, most notably increased EITC generosity, have restored or enhanced consumption insurance.

Stripdowns and bankruptcy: lessons from agricultural bankruptcy reform

One type of financial reform being proposed to deal with the aftermath of the housing crisis is allowing bankruptcy judges the authority to modify residential mortgages in a way referred to as a stripdown. The reform is seen by some as a partial solution to the rise in foreclosures and as a Pandora’s box by others. But the debate is not new one. The 1980s farm foreclosure crisis sparked similar proposals and concerns. Congress decided to enact legislation that contained a stripdown provision, resulting in the creation of Chapter 12 in the bankruptcy code. The effects of Chapter 12 stripdown authority after its enactment shed light on the efficacy of allowing bankruptcy judges similar authority for housing loans.Foreclosure ; Bankruptcy ; Agricultural credit ; Mortgage loans

Competition and productivity: a review of evidence

Does competition spur productivity? And if so, how does it do so? These have long been regarded as central questions in economics. This essay reviews the literature that makes progress toward answering both questions.Competition ; Monopolies ; Productivity