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. Author manuscript; available in PMC: 2009 Nov 10.
Published in final edited form as: Popul Stud (Camb). 2008 Mar;62(1):25–38. doi: 10.1080/00324720701788590

Table 3.

Example of calculation of crossover and breakeven ages for landless women

(A) (B) (A)*(B)*308 = (C) (D) (E) Σ(C)*(E)*365.25 = (F) Σ(D)*(E)*365.25 = (G)
Age group
end-point		 Daily work
hours		 Production
profile		 Daily production
(calories)		 Daily consumption
(calories)		 nLx Cumulative production
(calories)		 Cumulative consumption
(calories)
1 0.0 0.00 0 1043 0.92 0 351542
4 0.0 0.00 0 1344 2.57 0 1613766
7 2.1 0.47 302 1344 2.47 271875 2823863
10 8.1 0.58 1459 1140 2.42 1559110 3829655
13 6.6 0.71 1453 1399 2.39 2826168 5049755
16 9.8 0.86 2597 1567 2.36 5067057 6401801
22 8.7 0.91 2436 1598 4.63 9185630 9102208
25 9.6 0.95 2800 1598 2.26 11391141 10420435
30 9.6 0.95 2800 1598 3.67 14977218 12563821
35 9.6 0.95 2800 1598 3.55 18438240 14632463
40 9.6 0.95 2800 1598 3.41 21763226 16619796
45 9.6 0.95 2800 1598 3.26 24941943 18519705
50 9.6 0.95 2800 1598 3.09 27961604 20324547
55 9.6 0.95 2800 1598 2.90 30793127 22016939
60 9.6 0.95 2800 1598 2.66 33390189 23569195

Notes:

  • Production profile is PHigh and consumption profile is CLow

  • Daily production and consumption values apply to the middle of the age range for the row

  • Bolded values in columns (C) and (D) indicate the age by which crossover has occurred: 7.8

  • We multiply production by 308, which comes from Tables 2, because it is the average number of calories produced by an adult in one hour

  • Cumulative production and consumption values are achieved at the end of the age range for the row

  • Bolded values in columns (F) and (G) indicate the age by which breakeven has occurred: 21.6