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Having established that improved access to iodine substantially improved labor market outcomes, particularly for females, we next study the effects of this cognitive shock on other dimensions of life. Table 6 reports the results of our main regressions on educational attainment and marriage outcomes, restricting to the 1970–1980 census waves in order to focus on a sample of individuals old enough to have completed their schooling and made their first marriage decisions.

Table 6.
Effects of Salt Iodization on Education and Marital Outcomes
(1)(2)(3)(4)(5)(6)(7)
Years of Schooling1(Ever Married)Age at First MarriageSpouse's Years of Schoolingsinh-1(Spouse's Income)sinh-1(Family Income)1(Ever Married)
A. Females        
After × Goiter Rate 0.0712* 0.000541 0.232*** 0.0888** 0.00755 0.0177* −0.00488** 
 (0.0379) (0.00182) (0.0478) (0.0402) (0.0123) (0.00936) (0.00237) 
During × Goiter Rate 0.0359 0.000702 0.0394 0.0727*** 0.0277** 0.0113 0.000885 
 (0.0274) (0.00191) (0.0543) (0.0264) (0.0112) (0.00812) (0.00236) 
Age       0.0276*** 
       (0.000414) 
Observations 930,333 930,333 761,885 695,464 692,713 922,124 25,581,376 
Mean of dependent variable 11.31 0.951 21.43 11.31 11.05 11.18 0.731 
B. Males        
After × Goiter Rate 0.0313 0.00288 −0.0405 0.0189 0.0178 0.0168** 0.00388** 
 (0.0464) (0.00235) (0.0454) (0.0288) (0.0448) (0.00793) (0.00168) 
During × Goiter Rate 0.0990** 0.00220 −0.0355 0.0249 −0.00546 0.0202*** 0.00321 
 (0.0396) (0.00187) (0.0594) (0.0259) (0.0511) (0.00641) (0.00250) 
Age       0.0334*** 
       (0.000207) 
Observations 859,574 859,574 692,623 716,526 714,625 846,971 23,566,464 
Mean of dependent variable 11.45 0.937 24.16 11.59 5.833 11.35 0.641 
C. Female-male difference        
After × Goiter Rate 0.0399 −0.00234 0.273*** 0.0699** −0.0102 0.000901 −0.00875*** 
 (0.0369) (0.00355) (0.0575) (0.0262) (0.0499) (0.0103) (0.00294) 
During × Goiter Rate −0.0631** −0.00150 0.0749 0.0478* 0.0331 −0.00885 −0.00232 
 (0.0302) (0.00267) (0.0716) (0.0251) (0.0571) (0.00834) (0.00282) 
(1)(2)(3)(4)(5)(6)(7)
Years of Schooling1(Ever Married)Age at First MarriageSpouse's Years of Schoolingsinh-1(Spouse's Income)sinh-1(Family Income)1(Ever Married)
A. Females        
After × Goiter Rate 0.0712* 0.000541 0.232*** 0.0888** 0.00755 0.0177* −0.00488** 
 (0.0379) (0.00182) (0.0478) (0.0402) (0.0123) (0.00936) (0.00237) 
During × Goiter Rate 0.0359 0.000702 0.0394 0.0727*** 0.0277** 0.0113 0.000885 
 (0.0274) (0.00191) (0.0543) (0.0264) (0.0112) (0.00812) (0.00236) 
Age       0.0276*** 
       (0.000414) 
Observations 930,333 930,333 761,885 695,464 692,713 922,124 25,581,376 
Mean of dependent variable 11.31 0.951 21.43 11.31 11.05 11.18 0.731 
B. Males        
After × Goiter Rate 0.0313 0.00288 −0.0405 0.0189 0.0178 0.0168** 0.00388** 
 (0.0464) (0.00235) (0.0454) (0.0288) (0.0448) (0.00793) (0.00168) 
During × Goiter Rate 0.0990** 0.00220 −0.0355 0.0249 −0.00546 0.0202*** 0.00321 
 (0.0396) (0.00187) (0.0594) (0.0259) (0.0511) (0.00641) (0.00250) 
Age       0.0334*** 
       (0.000207) 
Observations 859,574 859,574 692,623 716,526 714,625 846,971 23,566,464 
Mean of dependent variable 11.45 0.937 24.16 11.59 5.833 11.35 0.641 
C. Female-male difference        
After × Goiter Rate 0.0399 −0.00234 0.273*** 0.0699** −0.0102 0.000901 −0.00875*** 
 (0.0369) (0.00355) (0.0575) (0.0262) (0.0499) (0.0103) (0.00294) 
During × Goiter Rate −0.0631** −0.00150 0.0749 0.0478* 0.0331 −0.00885 −0.00232 
 (0.0302) (0.00267) (0.0716) (0.0251) (0.0571) (0.00834) (0.00282) 

Standard errors, clustered by state of birth, in parentheses ***p < 0.01, **p < 0.05, and *p < 0.1. “Goiter Rate” is the goiter rate in the individual's state of birth from Love and Davenport (1920), scaled by the difference between the 75th and 25th percentile of the goiter distribution (0.71). “After” is a dummy equal to 1 for those born 1928 to 1931. “During” is a dummy equal to 1 for those born 1924 to 1927. These regressions use the 1970–1980 Censuses, restricting to individuals born from 1920 to 1931. All regressions include state of birth fixed effects; year of birth × census year dummies; census division of birth × birth year dummies; gender; race; and during and after dummies interacted with average state latitude and 1920 state-level female and black proportions. “1(Worked at least 40 weeks)” is conditional on having worked in the past year. “sinh-1(income variable)” takes the inverse hyperbolic sine of the relevant income variable (spouse's total income or total family income), including 0 s for those not working. Column 7 uses a panel data set, where each observation represents an individual age for each age from 14 to 45 (the 1st and 99th percentiles of age at first marriage).

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