This is the pollution data so loved by writers of papers on ridge regression. Source: McDonald, G.C. and Schwing, R.C. (1973) 'Instabilities of regression estimates relating air pollution to mortality', Technometrics, vol.15, 463- 482. Variables in order: PREC Average annual precipitation in inches JANT Average January temperature in degrees F JULT Same for July OVR65 % of 1960 SMSA population aged 65 or older POPN Average household size EDUC Median school years completed by those over 22 HOUS % of housing units which are sound & with all facilities DENS Population per sq. mile in urbanized areas, 1960 NONW % non-white population in urbanized areas, 1960 WWDRK % employed in white collar occupations POOR % of families with income < $3000 HC Relative hydrocarbon pollution potential NOX Same for nitric oxides SO@ Same for sulphur dioxide HUMID Annual average % relative humidity at 1pm MORT Total age-adjusted mortality rate per 100,000 36. 27. 71. 8.1 3.34 11.4 81.5 3243. 8.8 42.6 11.7 21. 15. 59. 59. 921.870 35. 23. 72. 11.1 3.14 11.0 78.8 4281. 3.5 50.7 14.4 8. 10. 39. 57. 997.875 44. 29. 74. 10.4 3.21 9.8 81.6 4260. .8 39.4 12.4 6. 6. 33. 54. 962.354 47. 45. 79. 6.5 3.41 11.1 77.5 3125. 27.1 50.2 20.6 18. 8. 24. 56. 982.291 43. 35. 77. 7.6 3.44 9.6 84.6 6441. 24.4 43.7 14.3 43. 38. 206. 55. 1071.289 53. 45. 80. 7.7 3.45 10.2 66.8 3325. 38.5 43.1 25.5 30. 32. 72. 54. 1030.380 43. 30. 74. 10.9 3.23 12.1 83.9 4679. 3.5 49.2 11.3 21. 32. 62. 56. 934.700 45. 30. 73. 9.3 3.29 10.6 86.0 2140. 5.3 40.4 10.5 6. 4. 4. 56. 899.529 36. 24. 70. 9.0 3.31 10.5 83.2 6582. 8.1 42.5 12.6 18. 12. 37. 61. 1001.902 36. 27. 72. 9.5 3.36 10.7 79.3 4213. 6.7 41.0 13.2 12. 7. 20. 59. 912.347 52. 42. 79. 7.7 3.39 9.6 69.2 2302. 22.2 41.3 24.2 18. 8. 27. 56. 1017.613 33. 26. 76. 8.6 3.20 10.9 83.4 6122. 16.3 44.9 10.7 88. 63. 278. 58. 1024.885 40. 34. 77. 9.2 3.21 10.2 77.0 4101. 13.0 45.7 15.1 26. 26. 146. 57. 970.467 35. 28. 71. 8.8 3.29 11.1 86.3 3042. 14.7 44.6 11.4 31. 21. 64. 60. 985.950 37. 31. 75. 8.0 3.26 11.9 78.4 4259. 13.1 49.6 13.9 23. 9. 15. 58. 958.839 35. 46. 85. 7.1 3.22 11.8 79.9 1441. 14.8 51.2 16.1 1. 1. 1. 54. 860.101 36. 30. 75. 7.5 3.35 11.4 81.9 4029. 12.4 44.0 12.0 6. 4. 16. 58. 936.234 15. 30. 73. 8.2 3.15 12.2 84.2 4824. 4.7 53.1 12.7 17. 8. 28. 38. 871.766 31. 27. 74. 7.2 3.44 10.8 87.0 4834. 15.8 43.5 13.6 52. 35. 124. 59. 959.221 30. 24. 72. 6.5 3.53 10.8 79.5 3694. 13.1 33.8 12.4 11. 4. 11. 61. 941.181 31. 45. 85. 7.3 3.22 11.4 80.7 1844. 11.5 48.1 18.5 1. 1. 1. 53. 891.708 31. 24. 72. 9.0 3.37 10.9 82.8 3226. 5.1 45.2 12.3 5. 3. 10. 61. 871.338 42. 40. 77. 6.1 3.45 10.4 71.8 2269. 22.7 41.4 19.5 8. 3. 5. 53. 971.122 43. 27. 72. 9.0 3.25 11.5 87.1 2909. 7.2 51.6 9.5 7. 3. 10. 56. 887.466 46. 55. 84. 5.6 3.35 11.4 79.7 2647. 21.0 46.9 17.9 6. 5. 1. 59. 952.529 39. 29. 75. 8.7 3.23 11.4 78.6 4412. 15.6 46.6 13.2 13. 7. 33. 60. 968.665 35. 31. 81. 9.2 3.10 12.0 78.3 3262. 12.6 48.6 13.9 7. 4. 4. 55. 919.729 43. 32. 74. 10.1 3.38 9.5 79.2 3214. 2.9 43.7 12.0 11. 7. 32. 54. 844.053 11. 53. 68. 9.2 2.99 12.1 90.6 4700. 7.8 48.9 12.3 648. 319. 130. 47. 861.833 30. 35. 71. 8.3 3.37 9.9 77.4 4474. 13.1 42.6 17.7 38. 37. 193. 57. 989.265 50. 42. 82. 7.3 3.49 10.4 72.5 3497. 36.7 43.3 26.4 15. 18. 34. 59. 1006.490 60. 67. 82. 10.0 2.98 11.5 88.6 4657. 13.5 47.3 22.4 3. 1. 1. 60. 861.439 30. 20. 69. 8.8 3.26 11.1 85.4 2934. 5.8 44.0 9.4 33. 23. 125. 64. 929.150 25. 12. 73. 9.2 3.28 12.1 83.1 2095. 2.0 51.9 9.8 20. 11. 26. 58. 857.622 45. 40. 80. 8.3 3.32 10.1 70.3 2682. 21.0 46.1 24.1 17. 14. 78. 56. 961.009 46. 30. 72. 10.2 3.16 11.3 83.2 3327. 8.8 45.3 12.2 4. 3. 8. 58. 923.234 54. 54. 81. 7.4 3.36 9.7 72.8 3172. 31.4 45.5 24.2 20. 17. 1. 62. 1113.156 42. 33. 77. 9.7 3.03 10.7 83.5 7462. 11.3 48.7 12.4 41. 26. 108. 58. 994.648 42. 32. 76. 9.1 3.32 10.5 87.5 6092. 17.5 45.3 13.2 29. 32. 161. 54. 1015.023 36. 29. 72. 9.5 3.32 10.6 77.6 3437. 8.1 45.5 13.8 45. 59. 263. 56. 991.290 37. 38. 67. 11.3 2.99 12.0 81.5 3387. 3.6 50.3 13.5 56. 21. 44. 73. 893.991 42. 29. 72. 10.7 3.19 10.1 79.5 3508. 2.2 38.8 15.7 6. 4. 18. 56. 938.500 41. 33. 77. 11.2 3.08 9.6 79.9 4843. 2.7 38.6 14.1 11. 11. 89. 54. 946.185 44. 39. 78. 8.2 3.32 11.0 79.9 3768. 28.6 49.5 17.5 12. 9. 48. 53. 1025.502 32. 25. 72. 10.9 3.21 11.1 82.5 4355. 5.0 46.4 10.8 7. 4. 18. 60. 874.281 34. 32. 79. 9.3 3.23 9.7 76.8 5160. 17.2 45.1 15.3 31. 15. 68. 57. 953.560 10. 55. 70. 7.3 3.11 12.1 88.9 3033. 5.9 51.0 14.0 144. 66. 20. 61. 839.709 18. 48. 63. 9.2 2.92 12.2 87.7 4253. 13.7 51.2 12.0 311. 171. 86. 71. 911.701 13. 49. 68. 7.0 3.36 12.2 90.7 2702. 3.0 51.9 9.7 105. 32. 3. 71. 790.733 35. 40. 64. 9.6 3.02 12.2 82.5 3626. 5.7 54.3 10.1 20. 7. 20. 72. 899.264 45. 28. 74. 10.6 3.21 11.1 82.6 1883. 3.4 41.9 12.3 5. 4. 20. 56. 904.155 38. 24. 72. 9.8 3.34 11.4 78.0 4923. 3.8 50.5 11.1 8. 5. 25. 61. 950.672 31. 26. 73. 9.3 3.22 10.7 81.3 3249. 9.5 43.9 13.6 11. 7. 25. 59. 972.464 40. 23. 71. 11.3 3.28 10.3 73.8 1671. 2.5 47.4 13.5 5. 2. 11. 60. 912.202 41. 37. 78. 6.2 3.25 12.3 89.5 5308. 25.9 59.7 10.3 65. 28. 102. 52. 967.803 28. 32. 81. 7.0 3.27 12.1 81.0 3665. 7.5 51.6 13.2 4. 2. 1. 54. 823.764 45. 33. 76. 7.7 3.39 11.3 82.2 3152. 12.1 47.3 10.9 14. 11. 42. 56. 1003.502 45. 24. 70. 11.8 3.25 11.1 79.8 3678. 1.0 44.8 14.0 7. 3. 8. 56. 895.696 42. 33. 76. 9.7 3.22 9.0 76.2 9699. 4.8 42.2 14.5 8. 8. 49. 54. 911.817 38. 28. 72. 8.9 3.48 10.7 79.8 3451. 11.7 37.5 13.0 14. 13. 39. 58. 954.442