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Journal of Population Sciences

Table 2 The total size of a cohort and its descendants, as calculated by projection and by Eq. (10), for NRR = 0.75 and μ = 29 years

From: The time to decline: tracing a cohort’s descendants in below replacement populations

(1)

(2)

(3)

(4)

(5)

Time (t) [years]

Projected total size [PT(t)]

Growth rate [PT(t)/PT(t − 5)]

Total size from Eq. (10)

Proportional error

0

1.0

   

5

1.0

1.0

  

10

1.0

1.0

  

15

1.0

1.0

  

20

1.1642

1.1642

  

25

1.4064

1.2081

  

30

1.5625

1.1110

  

35

1.6475

1.0544

  

40

1.7418

1.0572

  

45

1.8534

1.0641

  

50

1.9695

1.0626

  

55

2. 0730

1.0526

  

60

2.1651

1.0444

  

65

2.2544

1.0412

  

70

2.3417

1.0387

  

75

2.4244

1.0353

  

80

2.5023

1.0321

  

85

1.5763

0.6300

1.9352

− 0.2277

90

1.6474

1.0451

1.8420

− 0.1181

95

1.7153

1.0412

1.7533

− 0.0221

100

1.7796

1.0375

1.6689

0.0622

105

1.6764

0.9420

1.5885

0.0524

110

1.4923

0.8902

1.5120

− 0.0132

115

1.3916

0.9325

1.4392

− 0.0342

120

1.3594

0.9769

1.3699

− 0.0077

125

1.3153

0.9675

1.3039

0.0087

130

1.2515

0.9515

1.2411

0.0083

135

1.1809

0.9436

1.1813

− 0.0004

140

1.1206

0.9490

1.1244

− 0.0034

145

1.0698

0.9546

1.0703

− 0.0005

150

1.0197

0.9532

1.0187

0.0009

155

0.9697

0.9510

0.9697

0.000 03

160

0.9225

0.9513

0.9230

− 0.000 54

165

0.8785

0.9523

0.8785

− 0.000 06

170

0.8366

0.9524

0.8362

0.000 48

175

0.7962

0.9516

0.7960

0.000 26

180

0.7574

0.9514

0.7576

− 0.000 23

185

0.7209

0.9518

0.7211

− 0.000 28

190

0.6864

0.9521

0.6864

0.000003

195

0.6535

0.9520

0.6534

0.000 17

200

0.6219

0.9518

0.6219

0.000 08

  1. Notes: The initial cohort is age 0 at time 0. The 5-year stable growth rate is 0.9518. The proportional error in the Eq. (10) analytical projection in column (5) is calculated as [(2) − (4)]/(2), referring to columns (2) and (4)