American Journal of Economics
p-ISSN: 2166-4951 e-ISSN: 2166-496X
2012; 2(1): 25-36
doi: 10.5923/j.economics.20120201.04
Olatomide Waheed Olowa
Department of Agricultural Education, Federal College of Education (Technical), Akoka
Correspondence to: Olatomide Waheed Olowa , Department of Agricultural Education, Federal College of Education (Technical), Akoka.
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Copyright © 2012 Scientific & Academic Publishing. All Rights Reserved.
The paper discusses the concept of poverty and elucidates the various methods of measurement used in evaluating poverty. Causes of poverty in Nigeria were also brought into perspective. It was concluded that inadequate economic growth is the main cause of poverty in Nigeria.
Keywords: Nigeria, Poverty, Perspective, Alleviation
Cite this paper: Olatomide Waheed Olowa , "Concept, Measurement and Causes of Poverty: Nigeria in Perspective", American Journal of Economics, Vol. 2 No. 1, 2012, pp. 25-36. doi: 10.5923/j.economics.20120201.04.
![]() | Figure 1. The Food-Energy Intake Method |
The Sen index has a major drawback. It is more responsive to improvements in the headcount than it is to reduction in the income gap or to improvements in the distribution of income among the poor. This index indicates that the efficient way to reduce poverty is to help the least needy first and the neediest last. The physical quality of life index (PQLI): The PQLI is attributed to Morris (1979). It measures how well societies satisfy certain specific ‘life-serving social characteristics’ or ‘achieved well-being’ (Doessel and Gounder, 1994). Thus its focus is on social development. The PQL is based on three indicators: infant mortality, life expectancy and basic literacy. Computationally, PQL is given by:PQL = f (IM, e, It) Where IM = infant mortalitye = life expectancyLit = literacyThe indices formed from these three indicators are summed up and the average give the PQLI (physical quality of life index).
Where, IMI = infant mortality indexel = life expectancy indexLit = Literacy indexThe human development index (HDI): The HDI is the most recent composite index devised by the United Nations Development Programme (UNDP, 1990). This index focuses on human development. It incorporates income and non -income factors. Three factors- longevity, knowledge and income are the variables of the index. Longevity is measured by life expectancy at birth (e0), knowledge is measured in terms of literacy. The third variable is per capita income. Generally, therefore, UNDP’s human development HD is specified as:
Where,e0 = life expectancy at birth Lit = literacy rate Y = per capita income These three indicators-life expectancy, literacy, and the logarithm of real GDP per capita are specified at the national level as components of the index. By looking across a range of countries, the maximum and minimum values for each indicator are established (Ajakaiye and Adeyeye, 1999).Relative poverty measures: Relative poverty measures define the segment of the population that is poor in relation to the set income of the general population. Such a poverty line is set at one-half of the mean income, or at the 40th percentile of the distribution. There are two main kinds of relative measures. Average income, this is the average income of the poorest 40 percent of the population and/or the average income of the poorest 10 or 20 percent of the population. The second is the number or population of people whose incomes are less than or equal to predetermined percentage of the mean income say 50% or less of the mean income.Composite measure of poverty proposed by Foster, Greer and Thorbecke (FGT) (1984): Foster et al (1984) proposed a family of poverty indices, based on a single formula, capable of incorporating any degree of concern about poverty through the “poverty aversion” parameter, . This is the so-called P-alpha measures of poverty or the poverty gap index:
Zi s the poverty line, q is the number of households/persons below the poverty line, N is total sample population, Yi is the income of the household, and
is the FGT parameter, which takes the values 0, 1 and 2, depending on the degree of concern about poverty. The quantity in parentheses is the proportionate shortfall of income below the poverty line. By increasing the value of
the “aversion” to poverty as measured by the index is increased. For example, where there is no aversion to poverty,
= 0, the index is simply
This is equal to the head-count ratio. This index measures the incidence of poverty. If the degree of aversion to poverty is increased such that when
= 1, the index becomes
Here the head-count ratio is multiplied by the income gap between the average poor person and the poverty line. This index measures the depth of poverty and it is also referred to as income gap’ or ‘poverty gap’ measure. Although superior to P0, PI still implies uniform concern about the depth of poverty, in that it weights the various income gaps of the poor equally. P2 or FGT index allows for concern about the poorest of the poor through attaching greater weight to the poverty of the poorest than those just below the poverty line. This is done by squaring the income gap to capture the severity of poverty:
This index satisfies the Sen-Transfer axiom which requires that when income is transferred from a poor to a poorer person, measured poverty decreases. Another advantage of the P-alpha measures is their decomposability. The overall poverty can be expressed as the sum of groups; poverty weighted by the population share of each group.Thus,
Where j= 1,2,3 … m groups, Kj is population share of each group, and P j is poverty measure for each group. The contribution of each group, Cj, to overall poverty can then be calculated. The contribution to overall poverty, like in the case of inequality, well provides a guide as to where poverty is concentrated and where policy interventions should be targeted.