1. Day 11 Methodological Lecture Migration

2. Measuring migration Create a event variable from comparison of unique values of UNIQUE_VILLAGE_ID Make sure to exclude Guosantun 1780 and Aerjishan 1906. Make sure to exclude observations with missing values. – Some location names in the data were originally administrative units ( annotated with suo shu ge tun) and have been converted to missing. Because of problems in the original data, some people appear to move somewhere, then move back in the next register. – Need to address those in creation of a variable.

3. Creating a variable for village moves use "C:\Users\Cameron Campbe\Documents\Baqi\CMGPD-LN from ICPSR\ICPSR_27063\DS0001\27063-0001-Data.dta", clear merge 1:1 RECORD_NUMBER using "C:\Users\Cameron Campbe\Documents\Baqi\CMGPD-LN from ICPSR\ICPSR_27063\DS0003\27063-0003-Data.dta" drop if (DATASET == 10 & YEAR == 1780) | (DATASET == 25 & YEAR == 1906) drop if UNIQUE_VILLAGE_ID == -99 bysort PERSON_ID (YEAR): generate at_risk_move = PRESENT == 1 & _n < _N & YEAR[_n+1] == YEAR+3 bysort PERSON_ID (YEAR): generate next_move = (UNIQUE_VILLAGE_ID[_n+1] != UNIQUE_VILLAGE_ID) & at_risk_move bysort PERSON_ID (YEAR): generate move_back = next_move & UNIQUE_VILLAGE_ID[_n+2] == UNIQUE_VILLAGE_ID & _n+2 <= _N tab move_back if next_move bysort PERSON_ID (YEAR): replace move_back = 1 if next_move & _n < _N & UNIQUE_VILLAGE_ID[_n-1]==UNIQUE_VILLAGE_ID[_n+1] & UNIQUE_VILLAGE_ID != UNIQUE_VILLAGE_ID[_n+1] tab move_back if next_move replace next_move = next_move & (move_back == 0)

4. . bysort PERSON_ID (YEAR): generate move_back = next_move & UNIQUE_VILLAGE_ID[_n+2] == UNIQUE_VILLAGE > _ID & _n+2 <= _N. tab move_back if next_move move_back | Freq. Percent Cum. ------------+----------------------------------- 0 | 14,802 88.79 88.79 1 | 1,869 11.21 100.00 ------------+----------------------------------- Total | 16,671 100.00. bysort PERSON_ID (YEAR): replace move_back = 1 if next_move & _n < _N & UNIQUE_VILLAGE_ID[_n-1]==UN > IQUE_VILLAGE_ID[_n+1] & UNIQUE_VILLAGE_ID != UNIQUE_VILLAGE_ID[_n+1] (2773 real changes made). tab move_back if next_move move_back | Freq. Percent Cum. ------------+----------------------------------- 0 | 12,029 72.16 72.16 1 | 4,642 27.84 100.00 ------------+----------------------------------- Total | 16,671 100.00. replace next_move = next_move & (move_back == 0) (4642 real changes made)

5. keep if at_risk_move bysort YEAR: egen mean_next_move = mean(next_move) bysort YEAR: generate first_in_year = _n == 1 twoway bar mean_next_move YEAR if first_in_year & YEAR >= 1789, scheme(s1mono) xtitle("Year") ytitle("Prop. individuals changing village in next 3 years") /* Note that this is picking up if anyone in the household moves in the next 3 years */ bysort YEAR HOUSEHOLD_ID: egen hh_next_move = max(next_move) bysort YEAR HOUSEHOLD_ID: keep if _n == 1 bysort YEAR: egen mean_hh_next_move = mean(hh_next_move) bysort YEAR: replace first_in_year = _n == 1 twoway bar mean_hh_next_move YEAR if first_in_year & YEAR >= 1789, scheme(s1mono) xtitle("Year") ytitle("Prop. households changing village in next 3 years")

9. Illegal departure (tao) ABSCONDED – Indicates that a male is currently annotated in the register as tao. – Never annotated for females. EVER_ABSCONDED – Indicates that a male at some point in his life was annotated as tao, even if it wasn’t in this register. – May be used to exclude observations in mortality analysis, since recording of men ever identified as tao seems poor.

10. use "C:\Users\Cameron Campbe\Documents\Baqi\CMGPD-LN from ICPSR\ICPSR_27063\DS0001\27063-0001-Data.dta", clear merge 1:1 RECORD_NUMBER using "C:\Users\Cameron Campbe\Documents\Baqi\CMGPD-LN from ICPSR\ICPSR_27063\DS0003\27063-0003-Data.dta" generate at_risk_tao = ABSCONDED == 0 & PRESENT == 1 & NEXT_3 == 1 bysort PERSON_ID (YEAR): generate next_tao = at_risk_tao & _n < _N & ABSCONDED[_n+1] == 1 keep if at_risk_tao bysort YEAR: egen mean_next_tao = mean(next_tao) bysort YEAR: generate first_in_year = _n == 1 twoway bar mean_next_tao YEAR if first_in_year, scheme(s1mono) ytitle("Proportion of men absconding in next 3 years")