Despite the persistent logistics gap, income
alone cannot explain why performance varies
widely among countries in certain income
groups—particularly in the low- and middleincome
groups. As shown in previous editions,
high-income countries are heavily concentrated
in the top LPI quintile, but other
income groups are more dispersed. More
important, upper middle-income and lower
middle-income countries range from the bottom
LPI quintile to the top. Even low-income
countries range across all but the top quintile
(figure 1.5).