The infant mortality rate is the annual number of deaths of children under one year of age per 1 000 live births. Some international variation in infant mortality rates may be due to country variation in defining live children following birth. Most countries have no gestational age or weight limits for mortality registration. Minimal limits exist for Norway (to be counted as a death following a live birth, the gestational age must exceed 12 weeks) and in the Czech Republic, France, the Netherlands and Poland a minimum gestational age of 22 weeks and/or a weight threshold of 500 g is applied (EURO-PERISTAT Project 2008, Table 3.1, p. 40).
Household income and income inequality data are discussed in GE1 and EQ1.
The Gini coefficient is a measure of income inequality. Values range between 0 - perfect equality - and 1 - all income goes to one person.
One in 200 children born in the OECD died during infancy in 2008 on average (Panel A, Figure HE2.1). Infant mortality rates in OECD countries in 2008 ranged from lows of 2.5 or fewer deaths per 1 000 live births in Luxembourg, Slovenia, Iceland and Sweden, to highs of 15 and 17 infant deaths in Mexico and Turkey respectively. Infant mortality rates were also relatively high in Chile, the United States and the Slovak Republic.
All OECD countries have achieved good progress in reducing infant mortality rates over the last 25 years (Panel B, Figure HE2.1). The largest decline, by a considerable margin, was found in Turkey, followed by Mexico. High infant mortality countries, having greater scope for tried-and-true and low intervention cost reductions, have improved their positions by more than those with low infant mortality, who are approaching irreducible minima. Consequently there has been strong convergence in infant mortality rates across the OECD in the last 25 years. Those countries with very low rates may find it increasingly difficult to reduce rates further.
As with overall life expectancy, there was a little relationship between household income growth and infant mortality (Figure HE2.2) and income inequality changes and infant mortality (Figure HE2.3) over a long period. Overall, countries were not obviously constrained either by median household income growth or by income inequality rises in achieving improvements in life chances for their youngest citizens. The lack of a relationship is robust to excluding both Mexico and Turkey, outliers where falls in infant mortality were especially large and household income growth was low. Again, as with the analysis in HE1,
this analysis cautions against application of a simple private income-based explanation, either in terms of averages or inequality, to long duration changes in infant death rates.