Table 7. Effect of Follow-up Letter on Response Rates 
Percentages of Percentages of 
Received Contacts Responding Wings Received Total 
Follow-up Before After Before After Number 
Letter - Contacts Letter Letter Total Letter Letter Wings 
a 
Michigan 
yes 371 15.6 12.4 21.6 50.4 50.6 416 
no 372 16.1 09.9 20.7 63.9 36.1 442 
Illinois 
yes 469 23.7 11.5 2767 7304 26.6 723 
Arkansas 
yes 274 16.8 13.1 23.7 47.1 52.9 616 
no 273 19.8 09.5 22.7 66.9 33.1 431 

Table 8. Percentage of Respondents Who Returned A1j the Envelopes 
They Received Originally. 
Envelopes Arkansas Illinois Michigan Wisconsin States Combined 


Received % SeS« t> Se So h So Se h% SeSe Percentage Total 
4-8 29 14 36 72 15 59 12 112 16.5 257 
9-13 0 18 3 40 7 46 7 68 5. 1 172 
14-18 5 19 4 27 7 15 4 25 4.7 86 
19-23 6 17 0 22 0 11 0 14. 1.5 64 
25 8 60 5 58 7 27 12 40 8.3 185 
ss — a —— a ees = —— ee eS teens 
4-25 "9 «128 14 219 9 158 9 259 10. 6 764 

1/ Includes some hwaters who requested more envelopes. 
2/ Sample size. =a b= 
