FAS Student Papers

While the need for rigorous and affordable prostheses in developing countries is serious, little to none of these devices exist and are available to lower-limb amputees. In addition, pediatric amputees in low-income areas are further prohibited from accessing these technologies; the rapid growth rate of their limbs calls for frequent replacements of prostheses, making existing solutions economically unfeasible.

In this thesis, a model was generated to depict how the kinematic and kinetics of healthy pediatric gait vary with age. This model was then used to optimize the design of a passive ankle prosthesis, which uses a spring and damper system to store and release energy to the ankle joint. Most importantly, this system was designed to adapt to the changing gait pattern and dynamics of a pediatric amputee.

The presented paradigm—using a computer model to efficiently predict the gait produced by various prosthesis design—allows for the creation of affordable, accurate, and tailored devices for individuals who currently are forced to settle for one-size-fits all passive solutions. This approach promises to substantially increase the access to prostheses for children around the world.

90 Reasons is a list of prospective benefits cellular agriculture may offer upon global-scale introduction this century.

The use of affirmative action has been at the forefront of the debate regarding the fairness of the college admissions process for years. Utilizing data from the National Longitudinal Survey of Freshman (NLSF), M. Fischer and Massey (2007) test the effects of race-based admission policies. Providing a specific focus on cumulative GPA, they conclude that the effect of affirmative action is minimal. Testing the robustnessof this claim, I replicate their results. Their regression specification suffers from issues of high correlation between their SAT and individual affirmative action variable. When adjusting for these problems, affirmative action actually has a negative effect on cumulative GPA. There is a 0.10 reduction in GPA for every 100-point increase in the difference between an individual’s SAT score and the institutional average.

In their controversial work The Bell Curve, Charles Murray and Richard Herrnstein hypothesize that intelligence plays a significant role in determining later life outcomes. Using data from the 1979 National Longitudinal Survey of Youth, Herrnstein and Murray specifically claim that Youth IQ is more important than Parental Socioeconomic Status in affecting future odds of living in poverty. We explore their hypothesis using the same statistical decisions but on a new data set: the 1997 National Longitudinal Survey of Youth. Our findings mirror those of Herrnstein and Murray; IQ has a larger effect than socioeconomic status on the likelihood of being in poverty, though the overall effect of both is diminished. We find that increasing Youth IQ by one standard deviation is expected to decrease the odds of ending up in poverty by 35 percentage points, compared to the 13 percentage point decrease from similarly increasing Parental Socioeconomic Status.

The Bell Curve (Herrnstein and Murray (1994)) is a very controversial piece of economics literature. The Bell Curve, which examines the effect of IQ on various social problems, is broken down into four sections: “The Emergence of the Cognitive Elite”, “Cognitive Classes”, “Social Behaviors”, and “National Context.” For survey statistics, Herrnstein and Murray (1994) use the National Longitudinal Survey of Youth (NLSY) data from 1979, which includes 12,686 people from ages 14 to 22, and contains Socioeconomic status (SES), IQ, and other related data. Herrnstein and Murray (1994) generate IQ from the Armed Forces Qualification Test (AFQT), a test all entrants to the Army take as an intelligence or IQ test. The Bell Curve concludes that self-isolation of the “cognitive elite,” defined in terms of IQ, has led to class stratification. Herrnstein and Murray (1994) believe that IQ is the best and most robust measure that is correlated to many resulting social problems, including poverty. I replicate The Bell Curve results that relate SES and IQ to poverty. I then examine the robustness of their results by examining a variety of regression specifications. I find that IQ is more correlated with poverty than SES in every regression, regardless of what is included in the regression, by a factor of 3.

The Bell Curve by Charles Murray and Richard Herrnstein is one of the most controversial academic works of the last few decades. Using data from the National Longitudinal Survey of Youths (1979), we performed a number of regressions of poverty status in 1989 on parental socioeconomic status, IQ, race, sex, and age. We replicate their results which show that IQ is a more important predictor of poverty status than parental socioeconomic status (SES). We extend their analysis to other groupings and find that, while similar, the underlying relationship between the variables and poverty status varies across groups. We then compared ratios of the percentage of the top 25% to bottom 25% of either IQ or parental SES in poverty. We found that parental SES had three times the predictive power as SES for black respondents and twice the predictive power for Hispanic respondents over whites, also finding a greater proportion of respondents in poverty at all levels for minority groups than for white respondents with a similar relationship for females compared to males.

The Bell Curve, written by Murray and Herrnstein, is one of the most controversial books of the last few decades, exploring the role human intelligence plays in predicting a variety of social factors. I examine one of their more notorious conclusions that intelligence, as measured by an IQ test, is a stronger predictor for future poverty than Family's Socioeco­nomic Status. sing the National Longitudinal Survey of Youth (1979), we run regressions examining the relationship between Family SES, IQ test scores, and Age against probability of being in Poverty. Instead of using Bell Curve's method of dropping data that contained incomplete observations, we use an improved method that imputes missing data. i[y results show that IQ does indeed have a greater effect than parental SES on predicting Poverty if the individual is of less than average SES and IQ.

The debate over affirmative action has played a significant role in shaping the world of academia over the past several decades. Accordingly, researchers Mary Fischer and Douglas Massey attempt to evaluate many of the arguments surrounding the social policy in their paper “The effects of affirmative action in higher education.” Drawing from the National Longitudinal Survey of Freshman, the authors conclude that there is no basis for the Mismatch Hypothesis and only a limited statistical basis for Stereotype Threat. We replicated their results and extended their analysis by examining a variety of regression specifications including demographic information, socioeconomic background, and social preparedness. We find that their conclusions are robust and that there is no evidence for the Mismatch Hypothesis and only a limited amount of evidence for Stereotype Threat. This is good news for academic institutions as it demonstrates that affirmative action can be practiced without significant negative consequence to the peer group it claims to help.

Affirmative action in higher education has been controversial since 1961. The Source of the River (Douglas Massey and Fischer (2003)) uses the National Longitudinal Survey of Freshmen—a demographic and socioeconomic survey of nearly 4,000 students entering 28 highly selective colleges in 1999—to evaluate explanations of minority underachievement in college. The authors develop two measures of vulnerability to stereotype threat. The authors focus on the stereotype threat hypothesis, and conclude that stereotype threat undermines minority achievement. We replicate their results, and investigate the robustness of their specification. We find that their main conclusion is fragile: controlling for other demographic characteristics, the effect of stereotype threat becomes statistically insignificant.

The areas of concern within animal agriculture have become increasingly worse in the last few decades as the production capacity of animal products has increased rapidly. At the same time, the prospect of making animal products without animals, called Cellular Agriculture, has revealed itself scientifically, and is showing promise towards curbing the associated problems with animal agriculture -- ranging from public health and food scarcity, to animal welfare and ecological degradation. This modernization of agriculture calls to thought the innovators and trailblazing communities throughout history; for they too were once before the beginning path of their revolution. And so History & Neo works to address the question: How would the most influential people & civilizations throughout history have supported cellular agriculture?

History & the Neomnivore is a supplementary piece to the Neomnivore Trilogy.