Technological change in U.S. jet fighter aircraft

This paper quantitatively measures technological change in U.S. jet fighter aircraft from 1944 to the present day using the hedonic pricing approach. The technical and performance characteristics of jet fighters have changed dramatically between the time they were first developed at the beginning of the 1940s and the present. Parallel to this technological change there has been a sharp escalation in costs regarding the new generations of jet fighter aircraft. We estimate a measure of price for the performance and technical characteristics of these aircraft. Embodied technological change in jet fighter airframes is measured using quality-adjusted prices. Although the flyaway cost of jet fighter aircraft has soared, on average, by about 12.63% per year, the quality-adjusted aircraft cost has only risen by about 2.6% per year, a figure lower than the average observed general inflation rate for the period (around 4%). This represents an impressive average technological progress ratio of around 10% per year. A revealed preferences argument shows that the characteristic most valued by the government is stealth capability, followed by advanced avionics.     

Orthographic learning in Spanish children

In order to read fluently, children have to form orthographic representations. Despite numerous investigations, there is no clear answer to the question of the number of times they need to read a word to form an orthographic representation. We used length effect on reading times as a measure, because there are large differences between long and short words for unknown words, differences that disappear when reading frequent words. Two lists of new words (half short and half long) were presented to 102 second‐grade to sixth‐grade Spanish children, to be read aloud six times. One of the lists was presented as part of a story and the other in isolation. Comparison of the length effect at the first and sixth exposure showed large differences between short and long words in the first presentation and small differences at the sixth presentation, indicating that Spanish children develop representations of words after just a few repetitions.     

Altitude and wind effects on long jump performance with particular reference to the world record established by Bob Beamon

An analysis of long jump performance, including both the approach and aerial phases, is applied to Bob Beamon's legendary leap at the Mexico City Olympic Games of 1968. It is shown that the combined effects of altitude and wind assistance yielded an increment in the length of the jump of about 31 cm, compared to a corresponding jump at sea level under still air conditions. The main factor is shown to be the increased sprinting speed attained under favourable conditions of wind and altitude.     

Improving the Academic Performance of Non‐native English‐Speaking Students: the Contribution of Pre‐sessional English Language Programmes

There is an established, if weak, inverse relationship between levels of English language proficiency and academic performance in higher education. In response, higher education institutions (HEIs) insist upon minimum entry requirements concerning language for international applicants. Many HEIs now also offer pre‐sessional English courses to bring applicants up to the designated language requirement. This paper revisits the research into language proficiency and academic performance using data on all full‐time students (17,925) attending a major UK HEI in the academic year 2011–2012, 4,342 of whom were non‐native English speakers. The findings confirm that while higher International English Language Testing System (IELTS) marks at entry translate into higher grade point averages (GPAs), students who undertake pre‐sessional courses do notably worse in GPA terms than students who arrive with acceptable (for the course) IELTS scores. These findings suggest HEIs (and, by extension, international students) could benefit from a review regarding the appropriateness of current pre‐sessional English language proficiency programmes.