Department of Economics

Faculty of Economic and Management Sciences

Economic and Development Problems in South Africa and Africa

Session 9 – Primary Education in Southern Africa

& how to think…

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• Hand in first draft of thesis________________________________________

• Comparing South Africa with 3 neighbouring countries – cross national comparisons

• Understanding sample selection bias using education

• Important for test / life / thought !!• !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Aims for today

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1) Comparing education quality in Southern Africa

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RECAP - SA in regional context

WCA

LIM

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RECAP - Viva Mzansi

• Grade 6 13 years olds• Complete and utter disgrace – government failure on a

national scale• Wholesale failure of the government to provide the most basic

tool needed for mobility, or even dignified living.

27.2% 40.2%

Cross-national comparisons?

CountryTotal population (mil)

Adult literacy rate

Net Enrolment Rate (2008)

GNP/cap PPP US$ (2008)

Public Current expenditure on primary education per pupil (unit cost) 2007 – [PPP constant 2006 US$]

Survival rate to Grade 5: school year ending 2006

Botswana 1.92 83% 87% 13100 1228 83%Mozambique 22.38 54% 80% 770 791 64%Namibia 2.13 88% 89% 6270 668 98%South Africa 49.67 89% 87% 9780 1225 98%

[1] 2006 data[2] 2005 data[3] 2004 data[4] 2007 data[5] 2007 data from (DBE, Macro Indicator Trends in Schooling: Summary report 2011 2011, 25) since it was not available in UNESCO (2010)NER = The number of children of official primary school age (according to ISCED9726) who are enrolled in primary education as a percentage of the total children of the official school age population

•Are cross-national comparisons valid?• Inter-national heterogeneity?

• Population? Spending? • Sample Selection?

?

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Enrolments

Spending

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Sample Selection (TEST)• What is a sample?

•  An entity that is representative of a class; a specimen.•  A set of elements drawn from and analyzed to estimate the characteristics of a population

• What is the purpose of sampling?• Censuses are expensive• We still want to make inferences about a population (economics / politics / science

• What Does Sample Selection Bias Mean?‘A type of bias caused by choosing non-random data for statistical analysis. The bias exists due to a flaw in the sample selection process, where a subset of the data is systematically excluded (or included) due to a particular attribute. The exclusion of the subset can influence the statistical significance of the test, or produce distorted results.’• EXAMPLES?

• Attrition bias / Survivor bias (stocks / child illness)• Voluntary bias (smoking survey)• Bowls is the most dangerous sport on earth• Survey – NIDS numeracy / LFP• Others?

• Questions to ask:• “Is this representative of the population I’m interested in?• Is there any possible selection mechanism involved?

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10

Enrolment & Survival?

Quality vs Access?

Botswana Mozambique Namibia South Africa0102030405060708090

100

72.21

51.2

87.22 85.26

14.79

28.8

1.78 1.73999999999999

Enrollment and Dropout

Surviving portion of NER Dropout portion of NER

Net

Enr

ollm

ent

Ratio

(N

ER)

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Ability to correct / adjust?

Botswana

Mozambique

Namibia

South Africa

10.6238.41

21.570.31

13.6326.4127.26

42

89.3861.59

78.529.69

86.3773.5972.74

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Functional Literacy (adjusted for enrolment

and dropout)Functionally illiterate Functionally Literate

Botswana

Mozambique

Namibia

South Africa

22.4850.27

32.7381.53

47.6960.47

40.1754.91

77.5249.73

67.2718.47

52.3139.53

59.8345.09

Functional Numeracy(adjusted for enrolment

and dropout)Functionally Innumerate Functionally Numerate

Assumptions?

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Provincial heterogeneity?

NIA CAB

NAM ZAM TET MAN SO

FINH

GAZ MAP CID

Mozambiq

ue0.0

20.0

40.0

60.0

80.0

100.0

120.0

Provincial Distributions (Mozambique)Corrected for Enrollment and Dropout

Perc

enta

ge o

f pri

mar

y-ag

ed c

hild

ren

ch

ildre

n in

the

pop

ulat

ion

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Exercise

• In groups of 3

• Think of 1 example of sample selection bias that you have personally encountered.

• {it doesn’t have to be from an actual sample that was drawn}

• Think of 2 examples of sample selection bias that we have not mentioned yet

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Admin• Review due next week

(questions?)• 3 main points + 1

observation/comment• ‘What we know about AIDS’ (Nattrass,

2010)• 1 page – max 500 words – don’t make me

count!

• First week of October – consultations about essay – I will post consultation times

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Questions ???

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