Note :The table reports the second stage resgression estimates for the effect of smoking cessation on infant birth weight. ̂ p denotes the propensity score estimate in the first stage probit regression. The specification also includes indicators for birth orders, weight 77 Dependent Variable: birth weight (grams) ̂ p 1106.07 ̂ p × intermediate care -289.97 Married 46.77 (168.72) (135.93) (6.55) ̂ p 2 -647.97 ̂ p $^{2}$× Hispanic 295.44 Hispanic -135.88 (128.59) (104.16) (50.80) ̂ p × Hispanic -209.42 ̂ p $^{2}$× black 253.63 Black -294.97 (145.39) (84.89) (40.84) ̂ p × black -58.92 ̂ p $^{2}$× age 2125 206.27 Age 2125 39.82 (117.00) (76.73) (32.52) ̂ p × age 2125 -179.04 ̂ p $^{2}$× age 2630 280.49 Age 2630 25.60 (100.02) (77.35) (32.72) ̂ p × age 2630 -217.70 ̂ p $^{2}$× age 3135 389.70 Age 3135 31.38 (100.81) (82.29) (34.66) ̂ p × age 3135 -327.82 ̂ p $^{2}$× age 3640 311.94 Age 3640 -11.43 (107.27) (108.41) (46.52) ̂ p × age 3640 -230.64 ̂ p $^{2}$× age 41+ -18.82 Age 41+ -139.83 (144.42) (265.15) (119.87) ̂ p × age 41+ 198.31 ̂ p $^{2}$× high school grad. -155.27 High school grad. 45.12 (366.20) (64.56) (24.77) ̂ p × high school grad. 81.92 ̂ p $^{2}$× some college -197.64 Some college 90.66 (79.87) (81.64) (30.41) ̂ p × some college 82.72 ̂ p $^{2}$× college grad. -16.43 College grad. 198.00 (99.82) (177.45) (68.02) ̂ p × college grad. -174.91 ̂ p $^{2}$× post grad. -410.44 Post grad. 0.74 (233.59) (265.75) (118.50) ̂ p × post grad. 392.50 ̂ p $^{2}$× adequate care 357.39 Adequate care 237.31 (373.54) (105.89) (37.10) ̂ p × adequate care -520.47 ̂ p $^{2}$× intermediate care 198.06 Intermediate care 123.90 (127.37) (112.30) (39.95) Table C.2: Series estimation of the second stage regression