STAT 301 - Business Statistics
Class Activity: Hypothesis Testing and the Law
(counts as Lecture Review #15)

Statistical arguments play an important role in many legal cases involving (alleged) discrimination. In this activity you are analyzing the data underlying two such U.S. Supreme Court cases. In each case you are asked: Does the claim of discrimination appear warranted? You should provide both appropriate statistical analysis as well as some "in English" discussion about what your results mean.

Case #1:

In the 1960's, only males who were 21 years old and older were eligible for jury duty in Alabama. About 26 percent of the adult males in Talladega County, Alabama, at that time were black. The murder conviction of a black man in Talladega County was appealed to the Supreme Court on the grounds that there were no blacks on the jury, and indeed no black men had served on juries in Talladega County "within the memory of persons now living." The U.S. Supreme Court (Swain v. Alabama, 1965) denied the appeal, noting that there had been 8 blacks on the 100-person panel from which the final jury had been selected. (The prosecution had ruled out these eight with constitutionally protected peremptory challenges.)

Case #2:

The 1977 U.S. Supreme Court case Castaneda v. Partida involved a criminal trial that originated in Hidalgo County, Texas (on the U.S.-Mexico border). The defendant in the trial appealed his conviction by contending he had been denied his constitutional right to a trial by a jury of his peers. Specifically, he argued that the jury selection process systematically excluded Hispanics from jury service. Texas at the time employed a "key man" system for choosing jury pools. In this system, respected individuals in the county were identified, and requested to recruit reliable persons for jury service.

There were no current records identifying county residents by ethnicity. The county did have lists of people eligible for jury duty, as well as lists of those actually called for jury duty. Examination of the surname was used as a proxy for Hispanic ethnicity. At the time, there were 181,535 persons eligible for jury duty in the county, of whom 143,611 were Spanish-surnamed. Of 870 persons selected for jury duty, 339 were Spanish-surnamed.