QUESTION: Why would the Geographic Assessor not report COL values for some comparisons?
When a very expensive Base City is selected, it is possible that the default spending pattern (based on the National Average) will be “too rich” for the expensive Base City. For example, if you have selected New York - Manhattan as your base city, the costs to buy the National Average life-style in this relatively expensive city will exceed the spending level specified.
When this occurs, you can switch the expensive city to the destination and use the National Average as the base — this expresses the comparison in dollars relative to the Base City.
A more comprehensive alternative would be to continue your research using the Relocation Assessor. While you may still encounter this problem, the Relocation Assessor allows you to adjust the assumptions to make the Base City more “affordable,” such as lowering the housing square footage.