1. What is observational data? What is experimental data? Is the data analyzed in Table 1.1 observational or experimental? Is the data analyzed in Table 1.3 observational or experimental?
2. Consider Table 1.3 from Mastering Metrics. What is the average value of Family Income for individuals in the Catastrophic plan? (Hint: Answer is shown in the first column.)
3. Consider again Table 1.3. What is the average value of Family Income for individuals with any level of insurance? (Hint: this value is not reported in the table, but it can be determined with the information that is reported there. For example, from the information in the table, we know that
(Average family income of those with any sort of insurance) – (Average family income of those in the catastrophic plan) = -654.
From your answer to Question 2 above we know that Average family income of those in the catastrophic plan. Thus (Average family income of those with any sort of insurance) – (the number you found above) = -654. Substituting in the values in parentheses and rearranging gives the average family income of those with any sort of insurance.
4. Consider now Table 1.1, and compare and contrast differences in average income between groups with and without insurance there and in Table 1.3. In other words, in Table 1.1, are average incomes different among respondents with and without insurance? In Table 1.3, are average incomes different among respondents with insurance versus those with the catastrophic-only plan? Are your answers to these two questions the same or different? Why?
