Perspectives on the Budget Surplus

This paper provides alternative measures of federal budget surpluses over 10-year and long-term horizons. Official baseline budget forecasts are based on a series of statutory requirements that may be at variance with reasonable expectation. More plausible notions of current policy toward discretionary spending, taxes and retirement trust funds imply that surpluses over the next 10 years will be substantially smaller than the baseline forecasts indicate. Properly accounting for long-term imbalances in social security and the rest of the budget implies that, under plausible definitions of current policy, the federal government faces a long-term shortfall.

New Results on the Effects of Tax Policy on the International Location of Investment

We study the effects of tax laws on foreign direct investment (FDI) and direct investment abroad (DIA), distinguishing in each case between investment financed by retained earnings and investment financed by transfers from abroad. We find that tax policy, through its effect on the rate-of-return available in the U.S., has an important effect on the international location of investment. FDI in the U.S. is very sensitive to after-tax rates-of-return available here. U.S. direct investment abroad is also affected, although to a lesser extent. We use these estimates to examine the effects of the 1981-82 tax changes on the international location of investment. We estimate that the tax changes lowered annual DIA by $0.5 billion to$1.0 billion (2% to 4% of its 1980 value), and raised annual FDI by $2 billion to$4 billion (11% of 20% of its 1980 value). We also discuss the welfare effects of tax policy toward international investment. Our results suggest that the tax effects on the international location of investment are important. Tax policies, such as ACRS andthe ITC, which raise the after tax rate-of-return on new investment without losing revenue from previous investment, not only stimulate domestic fixed investment, but also attract additional investment from abroad. The additional investment supplements the domestic investment impact on productivity and raises corporate tax revenue. However, our results should be taken as preliminary estimates, not as definitive statements about the long-run impacts of tax policy.

Estimating Potential Ground and Surface Water Pollution from Land Application of Poultry Litter - II

In Arkansas, approximately 1 Tg of poultry (Gallus gallus domesticus) manure and litter is produced annually. These waste products are commonly applied to pastures as a soil amendment or fertilizer, but excessive application rates and poor management practices could result in nutrient contamination of ground and surface water. The purpose of this study was to: (1) assess the nutrient concentrations in poultry manure and (2) evaluate the nitrogen loss from land-applied poultry litter and manure due to ammonia volatilization and denitrification. Analyses for total Kjeldahl nitrogen (TKN), inorganic nitrogen (Ni), phosphorus (P), and potassium (K) were compared in 12 wet and dry hen manure samples. Drying the manure reduced the TKN from 57 to 40 g N/kg on a dry weight basis in wet and dry manure, respectively. The Ni in the manure was in the ammoniacal form with values of 19 and 2 g N/kg for wet and dry manure, respectively. The P and K levels were not influenced by drying the manure and had values of 24 and 21 g/kg, respectively. The results indicate that the nitrogen content of hen manure can be significantly reduced by drying the sample prior to analysis. In a 10-day laboratory study and an 11-day field study to evaluate ammonia volatilization from surface-applied hen manure, results indicated that 37% of the total nitrogen content of the manure was lost. The results indicated that a substantial amount of nitrogen in surface-applied poultry waste can be lost due to ammonia volatilization. Laboratory studies to evaluate denitrification in a Captina silt loam amended with 9 Mg/ha of poultry litter were conducted. When the soil was aerobically incubated for 168 h and then flooded for 66 h, the nitrate-nitrogen level decreased a net of 17 mg N/kg. The results indicated that, if the ammoniacal nitrogen in the litter is oxidized to nitrate under aerobic conditions and then the soil is flooded and available carbon is present, denitrification can occur rapidly. Results from these studies indicate that soil and environmental conditions playa critical role in determining the potential for nitrate pollution of ground and surface water when poultry manure and litter are surface-applied to pastures

A commentary on recent water safety initiatives in the context of water utility risk management.

Over the last decade, suppliers of drinking water have recognised the limitations of relying solely on end-product monitoring to ensure safe water quality and have sought to reinforce their approach by adopting preventative strategies where risks are proactively identified, assessed and managed. This is leading to the development of water safety plans; structured ‘route maps’ for managing risks to water supply, from catchment to consumer taps. This paper reviews the Hazard Analysis and Critical Control Point (HACCP) procedure on which many water safety plans are based and considers its appropriateness in the context of drinking water risk management. We examine water safety plans in a broad context, looking at a variety of monitoring, optimisation and risk management initiatives that can be taken to improve drinking water safety. These are cross-compared using a simple framework that facilitates an integrated approach to water safety. Finally, we look at how risk management practices are being integrated across water companies and how this is likely to affect the future development of water safety p

GULP: Capabilities and prospects

The current status and capabilities of the atomistic simulation code GULP are described. In particular, the differences between versions 1.3.2 and 3.0 are detailed, as well as a concise pointer to applications in computational crystallography

Does cognitive ability influence responses to the Warwick-Edinburgh Mental Well-Being Scale?

It has been suggested that how individuals respond to self-report items relies on cognitive processing. We hypothesized that an individual's level of cognitive ability may influence these processes such that, if there is a hierarchy of items within a particular questionnaire, as demonstrated by Mokken scaling, the strength of that hierarchy will vary according to cognitive ability. Using data on 8,643 men and women from the National Child Development Survey (1958 birth cohort; Power, & Elliott, 2006), we investigated, using Mokken scaling, whether the 14 items that make up the Warwick-Edinburgh Mental Well-Being Scale (Tennant et al., 2007)-completed when the participants were 50 years of age-form a hierarchy and whether that hierarchy varied according to cognitive ability at age 11 years. Among the sample as a whole, we found a moderately strong unidimensional hierarchy of items (Loevinger's coefficient [H] = 0.48). We split participants into 3 groups according to cognitive ability and analyzed the Mokken scaling properties of each group. Only the medium and high cognitive ability groups had acceptable (?0.3) invariant item ordering (assessed using the HT statistic). This pattern was also found when the 3 cognitive ability groups were assessed within men and women separately. Greater attention should be paid to the content validity of questionnaires to ensure they are applicable across the spectrum of mental ability