The text "1989" isn't in the article I linked. You may have meant "1988". But I'm not trying to assert that the headline of the article or the comparisons it makes are worthwhile. I'm just referencing some data points contained therein.
[0] - https://fred.stlouisfed.org/series/MEHOINUSWAA646N
[1] - https://www.huduser.gov/periodicals/ushmc/spring05/ushmc_05q...
If two partners are buying a house together (a fairly common occurrence) per capita ratios would treat both partners as an individual, but a household would help fix for that discrepancy.
Median household incomes take into account households of all sizes (1 person households to n-person households), and if you compare against median price, you can help reduce the risks of outliers tainting any comparison.