  Global concern regarding ultrafine particles (UFPs), which are particulate
matter (PM) with a diameter of less than 100nm, is increasing. These
particles-with more serious health effects than PM less than 2.5 micrometers
(PM2.5)-are difficult to measure using the current methods because their
characteristics are different from those of other air pollutants. Therefore, a
new monitoring system is required to obtain accurate UFPs information, which
will raise the financial burden of the government and people. In this study, we
estimated the economic value of UFPs information by evaluating the
willingness-to-pay (WTP) for the UFPs monitoring and reporting system. We used
the contingent valuation method (CVM) and the one-and-one-half-bounded
dichotomous choice (OOHBDC) spike model. We analyzed how the respondents'
socio-economic variables, as well as their cognition level of PM, affected
their WTP. Therefore, we collected WTP data of 1,040 Korean respondents through
an online survey. The estimated mean WTP for building a UFPs monitoring and
reporting system is KRW 6,958.55-7,222.55 (USD 6.22-6.45) per household per
year. We found that people satisfied with the current air pollutant
information, and generally possessing relatively greater knowledge of UFPs,
have higher WTP for a UFPs monitoring and reporting system. The results can be
used to establish new policies response to PM including UFPs.
