13. Discuss the findings and evaluate the models. Summarize the effect of Dist on years of education and any other findings from the analysis. Be sure to discuss the internal validity of the regressions that you used. Include a discussion of possible omitted variable bias, misspecification of the functional form of the regression, errors in variables, sample selection, simultaneous causality, and inconsistency of the OLS standard errors.

Dependent variable: smoker ed (1) (2) (3) (4) smkban -0. 047*#* (0.009) 0. 081+ dist -0. 037*** (0.013) (0. 026) I(dist2) 0. 005* (0. 002) female -0. 033** * 0. 143* ** 0. 143+# (0.009) (0. 050) (0. 050) age 0. 010* ** (0. 002) I (age2) -0. 0001* * (0. 00002) hsdrop 0 . 323*** (0. 020) hsgrad 0. 233*** (0.015) colsome 0. 164*** (0. 015) colgrad 0. 045#** (0. 016) bytest 0. 093** 0. 093* (0. 003) (0. 003) tuition -0. 191* -0. 193# (0. 101) (0. 101) black -0. 028* 0. 351* ** 0. 334+** (0.016) (0. 071) (0. 072) hispanic 0. 105*** 0. 362*** 0. 333+** (0. 014) (0. 077) (0. 079) shall -92. 721*** (13. 426) incarc rate 0 . 816* (0. 044) density 94. 669*** (5.428) avginc 1. 235 (3.207) pop 18. 506*** (1. 055) pb1064 11. 292 (6.864) pw1064 2. 702 (3.454) pm1029 9.317** (4.441) incomehi 0.372*#* 0. 369*** (0. 061) (0. 061) ownhome 0. 139* 0. 143** (0. 067) (0. 067) dadcoll 0.571* (0. 074) (0. 074) momco 1] 0. 378**# 0. 378*#* (0. 082) (0. 081) cue80 0. 029#** 0. 026*** (0. 010) (0. 010) s.twof980 -0. 043** -0. 043** (0. 020) (0. 020) Constant -0.014 -178. 778 8. 921#* 9. 012*** (0.043) (224. 010) (0. 252) (0. 256) observations 10,000 1, 173 3, 796 3, 796 R2 0. 057 0. 724 0. 284 0. 284 Adjusted R2 0. 056 0. 722 0. 281 Residual Std. Error 0.416 (df = 9989) 176.313 (df = 1164) 1.538 (df = 3783) 1.537 (df = 3782) F Statistic 60. 371** (df = 10; 9989) 381. 103** (df = 8; 1164) 124. 806*#* (df = 12; 3783) 115.608*#* (df = 13; 3782)Series in Data Set Name Desrciption ed Years of Education Completed (See below) female 1 = Female/0 = Male black 1 = Black/0 = Not-Black Hispanic 1 = Hispanic/0 = Not-Hispanic bytest Base Year Composite Test Score. (These are achievement tests given to high school seniors in the sample) dadcoll 1 = Father is a College Graduate/ 0 = Father is not a College Graduate momcoll 1 = Mother is a College Graduate/ 0 = Mother is not a College Graduate incomehi 1 = Family Income > $25,000 per year/ 0 = Income