MR Microinsurance_2012_03_29.indd - International Labour ...

166 Health insurance
Th is assumption was tested further with the data from three studies
reviewed. Gustafson-Wright et al. (2009) showed that WTP expressed as a
percentage of consumption/expenditure was 11.4 per cent among the poorest
quintile, but only 1.2 per cent among the richest quintile. Dror et al. (2007)
reported that the median value of WTP as a percentage of income decreased
from 1.79 per cent among the poorest quintile to 0.84 per cent among the
richest quintile, and this negative correlation was signifi cant. Dong et al. (2005)
provided the value of WTP for fi ve income quintiles and the average income
proxy (consumption) for these quintiles, which enables us to calculate WTP
relative to income/expenditure; his results show that WTP was 18.9 per cent
among the poorest quintile, and only 0.9 per cent among the richest quintile.
We therefore conclude that, while nominal WTP levels increase when household
incomes grow, they decrease dramatically as income increases when WTP
is measured as a share of income.
Most studies also examined the association between WTP and other sociodemographic
variables. Table 7.4 contains the summary results.
Table 7.4 Association of WTP with socio-economic parameters
Authors I/HH Gender Education HH size Age Insurance experience
Walraven HH+I n.d. n.d. n.d. n.d. n.d.
Asenso-Okyere et al. HH m>f + n.d. n.s. n.s.
Mathiyazhagan HH n.d. + + n.s. n.d.
Masud et al. HH n.d. n.d. n.d. n.d. n.d.
Dong et al. HH n.s. + n.s. n.s. n.d.
I m>f + n.d. – n.d.
Binam et al. HH m>f n.s. n.d. n.s. n.d.
Asgary et al. HH n.d. + n.s. + n.s.
Asfaw and Braun HH n.s. + n.d. n.d. n.d.
Bärnighausen et al. I f>m + n.d. – n.d.
Ying et al. I m>f + n.d. – n.d.
Dror et al. HH m>f + (>11y) +,– (PP) – +
Lofgren et al. HH n.s. + n.d. – n.s.
Gustafsson-Wright et al. HH m>f + n.s. – n.d.
Onwujekwe et al. HH m>f + – (PP) n.s. n.d.
I m>f + n.s. + +
I = individual; HH = household; n.d. = not determined; n.s. = not signifi cant; PP = persons in household.
As is often assumed, education is a positive explanatory variable of WTP in
most cases.
Th e results (shown in Table 7.4) also suggest that in most cases, males were
willing to pay more than females. As for age, fi ve studies showed no signifi cant
eff ect of age on WTP, and six reported a negative correlation. Th ere is no intui-