Instructions

Questions

Question 1 [85 points]

This is the only questions for this problem set. In this question, you will use the 2009 and 2015 Residential Energy Consumption Survey RECS data to profile the quantities and types of televisions in US homes.

  1. [30 points] Using the 2009 RECS data, estimate the mean or proportion, as appropriate, for the following variables by census division (DIVISION) and urban/rural (UR or UATYP10) status:

    1. number of televisions (TVCOLOR),
    2. display type for most used television (TVTYPE1).
  2. [30 points] Repeat part “a” using the 2015 data RECS data.

  3. [25 points] For each set of estimates from the prior two parts, estimate the change from 2009 to 2015. To compute the variance of each change, assume the 2009 and 2015 estimates are independent. That is if \((\hat \theta_1, \hat v_1)\) and \((\hat \theta_2, \hat v_2)\) are the estimates and variances for 2009 and 2015, respectively, then the differences and their variances are: \((\hat \theta_2 - \hat \theta_1, \hat v_1 + \hat v_2)\).

For full credit, your solution should:

  • Provide 95% confidence intervals using the replicate weights for all point estimates presented in tables or figures. Estimate the variance \(\hat{v}(\hat{\theta})\) of your estimates as indicated in the documentation and use \(\hat\theta \pm \Phi^{-1}(.975) \sqrt{\hat v(\hat \theta)}\) as your interval.

  • Present all three parts together in a cohesive fashion. You may choose to organize this either by variable, by estimate (2009 estimate, 2015 estimate, difference), or by census division. Choose an organization to emphasize what you see as the most interesting findings. Use aesthetics such as color and/or facets to help with organization.

  • Provide both figures and tables of the final results.

  • Write your code in a manner that avoids excessive repetition.

Notes:

  • The replicate weights for the 2015 data are included in the data file.
  • The replicate weights for the 2009 data are distributed separately. You can find a link to the weights on the same page as the 2009 data.