Table 3. Car model mean values by model year CARB Obs MPG WEIGHT POWER = 1 Year N mean mean mean N Table 4. OLS tests of 1978 420 420 22.0 3,370 111 explanations for last gasps dependent variable: MPG 1979 436 436 22.2 3,234 107 1980 621 564 20.2 3,737 121 1981 618 542 22.0 3,664 117 1982 754 633 23.9 3,491 109 1983 797 637 24.7 3,478 107 1984 558 378 25.7 3,307 107 1985 778 448 25.7 3,376 114 1986 786 322 25.5 3,436 121 1987 804 208 25.6 3,441 124 1988 777 96 25.5 3,499 132 1989 738 59 25.4 3,522 133 1990 802 24 25.4 3,561 139 1991 817 15 25.4 3,549 145 1992 799 11 25.0 3,647 152 Total or 10505 4793 24.5 3,497 124 Wtd. Avg. (1) (2)
Table 3. Car model mean values by model year Year Obs N CARB = 1 N MPG mean WEIGHT mean POWER mean 1978 420 420 22.0 3,370 111 1979 436 436 22.2 3,234 107 1980 621 564 20.2 3,737 121 1981 618 542 22.0 3,664 117 1982 754 633 23.9 3,491 109 1983 797 637 24.7 3,478 107 1984 558 378 25.7 3,307 107 1985 778 448 25.7 3,376 114 1986 786 322 25.5 3,436 121 1987 804 208 25.6 3,441 124 1988 777 96 25.5 3,499 132 1989 738 59 25.4 3,522 133 1990 802 24 25.4 3,561 139 1991 817 15 25.4 3,549 145 1992 799 11 25.0 3,647 152 Total or Wtd. Avg. 10505 4793 24.5 3,497 124 Table 4. OLS tests of explanations for last gasps dependent variable: MPG (1) (2)