Forecasts now treat South Korea's entry into the $40,000 range for gross national income per capita as effectively settled for this year. It would come twelve years after the country first crossed $30,000 in 2014.

Per-capita GNI divides income earned by nationals at home and abroad by the population and is converted into dollars for international comparison, which means exchange-rate movements feed directly into the figure.

Why it took twelve years

Several factors combined to stretch the climb from $30,000 to $40,000 over twelve years. Alongside slower growth, the won was weak through much of the period, holding down income measured in dollars.

Demography played a part too. As the denominator shrinks, the per-capita figure rises on its own. That some of the recent improvement comes from population decline is a point analysts say warrants care in interpretation.

The gap between the number and the feeling

A rising national income measure is not the same as households feeling better off. The share of GNI that actually reaches households, measured as gross disposable income of households, has remained below the average of comparable economies.

Add housing and education costs and the result is the familiar response that $40,000 on paper is not visible in daily life. The figure is an average, and averages conceal distribution.

Chinese households in Korea depend relatively heavily on small business income, and trade associations say they are shaped more by sector conditions and rents than by aggregate indicators.

Statistical authorities stress that the number remains a projection until annual figures are confirmed. Where the exchange rate settles by year-end still leaves room for the final reading to shift.