Busan measures container throughput. It measures film festival attendance. It measures quarterly youth out-migration. But it does not measure foreign length of stay, youth return rates, builder density, or visitor trust indices during major events. This essay is the ninth in Busanloop's "18 Questions for Next Busan" series, published six days before Busan's June 3, 2026 mayoral election. Drawing on the 1956 paper by V. F. Ridgway that originated the business proverb "what you can't measure, you can't manage" — and warned against its indiscriminate use — it reframes the role of measurement in city operation. The essay's thesis is plain: the list of what Busan doesn't measure is nearly identical to the list of where Busan has not built trust infrastructure. Measurement does not produce operation. Trust does. Measurement is the tool that tracks whether trust is growing. The deeper reason Fukuoka grew thirteen years ahead was not that it measured numbers, but that it measured whether its city was trusted by outsiders. The piece closes by proposing four indicators the next Busan must begin to measure: (1) stay indicator, (2) return indicator, (3) builder indicator, (4) trust indicator. None measure trust directly; all measure the results of trust. This essay seals the series' central frame in a single word — trust — and the remaining essays Q10–Q18 will explore the different faces of trust in a city. This is the English variant. Korean original: https://doi.org/10.5281/zenodo.20411922
Hyunseung Kim (Wed,) studied this question.