H-alpha synoptic charts of solar activity during the first year of solar cycle 20, October 1964 - August 1965

Solar activity during the period October 28, 1964 through August 27, 1965 is presented in the form of charts for each solar rotation constructed from observations made with the chromospheric H-alpha spectra line. These H-alpha synoptic charts are identical in format and method of construction to those published for the period of Skylab observations. The sunspot minimum marking the start of Solar Cycle 20 occurred in October, 1964; therefore, charts represent solar activity during the first year of this solar cycle

Following in Your Parents' Footsteps? Empirical Analysis of Matched Parent-Offspring Test Scores

In this paper, we explore whether an intergenerational relationship exists between the reading and mathematics test scores, taken at ages 7, 11 and 16, of a cohort of individuals born in 1958 and the equivalent test scores of their offspring measured in 1991. Our results suggest that how the parent performs in reading and mathematics during their childhood is positively related to the corresponding reading and mathematics test scores of their offspring as measured at a similar age. Our findings imply that parental ability in numeracy and literacy as a child is positively associated with the ability in numeracy and literacy of their offspring. With respect to gender, a father´s (mother´s) test score generally has a positive influence on the test scores of their daughter (son)

Optimal redesign study of the harm wing

The purpose of this project was to investigate the use of optimization techniques to improve the flutter margins of the HARM AGM-88A wing. The missile has four cruciform wings, located near mid-fuselage, that are actuated in pairs symmetrically and antisymmetrically to provide pitch, yaw, and roll control. The wings have a solid stainless steel forward section and a stainless steel crushed-honeycomb aft section. The wing restraint stiffness is dependent upon wing pitch amplitude and varies from a low value near neutral pitch attitude to a much higher value at off-neutral pitch attitudes, where aerodynamic loads lock out any free play in the control system. The most critical condition for flutter is the low-stiffness condition in which the wings are moved symmetrically. Although a tendency toward limit-cycle flutter is controlled in the current design by controller logic, wing redesign to improve this situation is attractive because it can be accomplished as a retrofit. In view of the exploratory nature of the study, it was decided to apply the optimization to a wing-only model, validated by comparison with results obtained by Texas Instruments (TI). Any wing designs that looked promising were to be evaluated at TI with more complicated models, including body modes. The optimization work was performed by McIntosh Structural Dynamics, Inc. (MSD) under a contract from TI

PUTTING THE "ECON" INTO ECONOMETRICS

Should econometricians always incorporate economic theory in their models or only when unrestricted estimators are found to violate an inviolable theory? Using Monte Carlo experiments, we find that econometricians should use economic theory to the fullest extent possible. To paraphrase Leamer's classic article, we should put the "econ" into econometrics.Research Methods/ Statistical Methods,

NONCONSTANT PRICE EXPECTATIONS AND ACREAGE RESPONSE: THE CASE OF COTTON PRODUCTION IN GEORGIA

An adaptive regression model is used to examine the relative importance of cash and government support prices in determining cotton production over time. The results show that the cash price is more important as a source of price information for cotton producers than the government program price. The cash price was shown to have a greater influence on acreage response in every year, including periods thought to be dominated by government commodity programs.Adaptive regression, Cotton acreage response, Price expectations, Crop Production/Industries,

ECONOMIC CRITERIA FOR EVALUATING COMMODITY PRICE FORECASTS

Forecasts of economic time series are often evaluated according to their accuracy as measured by either quantitative precision or qualitative reliability. We argue that consumers purchase forecasts for the potential utility gains from utilizing them, not for their accuracy. Using Monte Carlo techniques to incorporate the temporal heteroskedasticity inherent in asset returns, the expected utility of a set of qualitative forecasts is simulated for corn and soybean futures prices. Monetary values for forecasts of various reliability levels are derived. The method goes beyond statistical forecast evaluation, allowing individuals to incorporate their own utility function and trading system into valuing a set of asset price forecasts.Commodity prices, Forecast evaluation, Value of information, Consumer/Household Economics,

THE EFFECT OF GOVERNMENT PROGRAMS ON ACREAGE RESPONSE OVER TIME: THE CASE OF CORN PRODUCTION IN IOWA

Corn acreage response in Iowa is examined using a time-varying parameter regression model. Separate estimates of the permanent portion of the parameter vector are obtained for each year over the period 1957-82. The estimated elasticities are grouped into “program” and “nonprogram” periods. The results indicate corn acreage response is more own-price elastics, and the elasticity is less variable under government acreage control programs than under a “nonprogram” regime. The assumption of parameter constancy is shown to be inappropriate for modeling Iowa corn acreage response over time.Agricultural and Food Policy, Crop Production/Industries,

The impact of distance to nearest education institution on the post-compulsory education participation decision

This paper uses data sources with the unique capacity to measure distances between home addresses and education institutions, to investigate, for the first time, the effect that such distance has on an individual´s post–compulsory education participation decision. The results show that there is no overall net effect. However, when attention is focussed on young people who are on the margin of participating in post–compulsory education (according to their prior attainment and family background) and when post–compulsory education is distinguished by whether it leads to academic or vocational qualifications, then greater distance to nearest education institution is seen to have a significant impact on the decision to continue in full–time post–compulsory education. This finding has relevance for education participation in rural areas relative to urban areas

MULTIPRODUCT PRODUCTION CHOICES AND PESTICIDE REGULATION IN GEORGIA

An increasing emphasis on surface and groundwater quality and food safety may result in some form of pesticide regulations. A restricted profit function model of Georgia agriculture is used to examine the short-run effects of 2 and 5 percent reductions in all pesticides. Point estimates of short-run impacts, along with their 90 percent confidence intervals are presented.Agricultural and Food Policy,