conclusion

The Historical Context and Rising Power of Data

• Evolution of Data Accessibility:     * In the recent past, information was significantly harder to gather and more expensive to analyze.     * Analyzing one million credit card transactions a few decades ago involved physical paper receipts and a lack of personal computers for data processing.

• Data Scarcity During the Great Depression:     * The U.S. government lacked official statistics on unemployment and Gross Domestic Product ($\text{GDP}$).     * In $1930$, Herbert Hoover inaccurately declared the Great Depression over based on outdated information.     * Hoover claimed in a State of the Union address that $2.5 \times 10^{6}$ Americans were out of work; the reality was $5 \times 10^{6}$ jobless citizens, with unemployment increasing by $1 \times 10^{5}$ every week.     * James Surowiecki observed in The New Yorker that "Washington was making policy in the dark."

• Modern Data Proliferation:     * Society is now "awash in data," allowing statistical tools to address significant social challenges across various sectors.

The Future of Football and Head Trauma

• Malcolm Gladwell’s Thesis ($2009$):     * Posed the question in The New Yorker: "How different are dog fighting and football?"     * The comparison arose as quarterback Michael Vick was reinstated in the NFL following a prison sentence for dog fighting, coinciding with emerging data on football-related brain trauma.

• Evidence of Neurological Damage:     * Head trauma in football is associated with depression, memory loss, dementia, and other neurological disorders.     * Case Study: Dave Duerson: A former safety and Super Bowl winner for the Chicago Bears who committed suicide by shooting himself in the chest, specifically requesting his brain be studied post-mortem.

• Statistical Findings:     * A phone survey of $1,000$ randomly selected former NFL players (with at least $3$ years in the league) found:         * For players over $50$, the rate of diagnosis for dementia or Alzheimer’s was $6.1\%$, which is $5$ times the national average.         * For younger players, the diagnosis rate was $19$ times the national average.

• Scientific Research:     * Ann McKee (Veterans Hospital, Bedford, MA): Documented the buildup of abnormal proteins called "tau" in the brains of athletes, leading to Chronic Traumatic Encephalopathy ($\text{CTE}$), a progressive neurological disorder.     * Kevin Guskiewicz (Sports Concussion Research Program, UNC): Used sensors in helmets to record impact force. Data shows players receive blows equivalent to a car crash windshield impact at $25\,\text{mph}$.

• Statistical Uncertainties:     * Questioning if current findings represent a "cluster" or statistical aberration.     * Investigating causality: Is damage caused by the sport itself, or other factors like steroid use or the predispositions of men who choose contact sports?

• Ethical Implications:     * Gladwell argues that dog fighting became unacceptable because the owner submits an animal to suffering for entertainment and profit; statistics are currently being used to determine if football faces a similar moral or regulatory reckoning.

The Rising Incidence of Autism

• Current Statistics (CDC $2012$):     * $1$ in $88$ American children was diagnosed with an Autism Spectrum Disorder ($\text{ASD}$) based on $2008$ data.     * The rate has climbed from $1$ in $150$ in $2002$ and $1$ in $110$ in $2006$, nearly doubling in less than a decade.     * Boys are $5$ times as likely to be diagnosed as girls.

• Epidemic of Autism vs. Epidemic of Diagnosis:     * Increased awareness among parents, doctors, and teachers may lead to more diagnoses of cases previously labeled as "learning disabilities."

• The Burden of ASD:     * The average lifetime cost of managing an ASD for a single individual is $\$3.5 \times 10^{6}$.

• Statistical Inquiries into Causality:     * Environmental/Demographic Factors: A UC Davis study identified $10$ locations in California with autism rates double that of surrounding areas; these clusters were neighborhoods with white, highly educated parents.     * Genetic Factors: Research on twins shows the likelihood of both children having ASD is higher among identical twins than fraternal twins.

• Debunking Misconceptions:     * Vaccines and Thimerosal: Despite claims by individuals like Congressman Dan Burton (whose grandson became autistic after receiving multiple shots containing mercury-based thimerosal), statistics show no link.     * Autism rates did not decline when thimerosal was removed from the MMR vaccine, nor are rates lower in countries that never used it.     * Confusion between correlation and causation persists because ASD symptoms often appear between a child's first and second birthdays, coinciding with vaccination schedules.

Identifying and Rewarding Teacher Quality

• Value-Added Assessments:     * Evaluating teachers by measuring student progress over time, rather than absolute test scores.     * Statistical models can refine this by accounting for student demographics (race, income, prior performance/aptitude).

• Implementation and Controversy:     * New York City ($2012$): Published ratings for $18,000$ teachers based on value-added data.     * Los Angeles ($2010$): Similar rankings published by the Los Angeles Times.     * U.S. Secretary of Education Arne Duncan supports these measures, stating, "Silence is not an option."     * Teachers' unions oppose this, with the NYC union spending $\$100,000$ on ads claiming "This Is No Way to Rate a Teacher."

• The "Noise" in Educational Data:     * Doug Staiger (Dartmouth College): Notes that results for a single teacher are "noisy" due to random factors (e.g., a broken air conditioner on test day).     * The year-to-year correlation in performance for a single teacher is approximately $0.35$. This is oddly identical to the year-to-year correlation for Major League Baseball players' batting averages or $ERA$.

• Air Force Academy Study (Scott Carrell and James West):     * Cadets were randomly assigned to standardized core courses (e.g., introductory calculus) to eliminate selection effects.     * Findings: Less experienced professors with fewer advanced degrees produced students with higher scores in intro courses and better student evaluations.     * The Twist: Students of experienced, highly credentialed (often "crusty") professors performed better in follow-on courses.     * Interpretation: Less experienced teachers may "teach to the test," whereas experienced professors focus on core concepts that matter long-term.

Statistical Tools in Fighting Global Poverty

• Esther Duflo’s Approach:     * Duflo (MIT), winner of the John Bates Clark Medal ($2010$), uses randomized controlled experiments ($\text{RCTs}$) to test interventions in developing countries.

• Addressing Teacher Absenteeism in India (Rajasthan):     * A sample of $60$ one-teacher schools was given cameras with tamperproof date/time stamps; teachers took photos with students to prove attendance for a bonus.     * Absenteeism dropped by $50\%$ compared to a control group of $60$ schools; test scores and graduation rates increased.

• Fertilizer Use in Kenya:     * Farmers often fall into a "poverty trap" where they lack cash for fertilizer at planting time.     * Duflo found that offering free fertilizer delivery immediately after harvest (when farmers had cash) increased use by $10$ to $20$ percentage points.

• Gender and Financial Responsibility (Côte d'Ivoire):     * Different crops respond to rainfall differently: Men grow cocoa and coffee; women grow plantains and coconuts.     * Duflo found that when women’s crops flourished, they spent extra cash on family food; when men's crops flourished, they did not.

Data Privacy and Ethics

• Predictive Analytics at Target:     * Target uses a "pregnancy prediction score" based on $25$ products (e.g., unscented lotion, vitamin supplements, large bags of cotton balls) to identify women in their second trimester.     * Case Study: A Minneapolis father complained to Target about his high school daughter receiving baby coupons, only to discover later she was indeed pregnant and due in August.     * Masking Tactics: Companies often mix "spooky" targeted coupons (like diapers) with random items (like lawn mowers or bowling socks) to hide how much they know.

• The Value of Facebook:     * Investors value Facebook for its data on user behavior, locations, and spending habits, rather than its social utility.     * Chris Cox (Facebook VP): "The challenge of the information age is what to do with it."

• Government and Law Enforcement:     * Surveillance: GPS tracking and facial recognition technology.     * Legal Precedent: In United States v. Jones ($2012$), the U.S. Supreme Court ruled unanimously that police cannot attach GPS tracking devices to private vehicles without a warrant.     * DNA Databases: Governments debate whether to include DNA from all citizens, all arrestees, or only convicted criminals.

• Final Conclusion:     * Statistics is a powerful tool, similar to fire, knives, or automobiles; it enhances life when used wisely but causes problems if abused.     * Math cannot replace human judgment.