Category Origins Grade?
The average Niche grade of the incoming population, weighted by net migration nationwide.

How it's calculated:
• For each origin ZIP nationwide, we convert its Niche letter grade to the 0–100 percentile scale.
Market-Level Netting: We calculate the total net migration from that ZIP to the entire destination market.
Net-Only Clamping: If the origin ZIP has a positive net flow, we use that net volume as the weight.
• ZIP codes with negative net flows are excluded.
• Sum all weighted origin percentiles and divide by the total net-attraction volume.
• Convert the result back to a letter grade for display.
Main Market Grade?
Population-weighted average of Niche grades across all ZIP codes in the main market.

How it's calculated:
• For each ZIP code in the main market, we take its Niche letter grade and convert it to a 0–100 percentile scale.
• Multiply each percentile by the ZIP's current adjusted population.
• Sum all weighted percentiles and divide by the total population of all ZIPs with available Niche data.
• Convert the weighted average back to a letter grade for display.
DifferenceDiff?
Difference in percentile scores (0–100 scale).

Positive values indicate categories where the destination market has a better grade than the weighted origins—these are the quality-of-life characteristics currently drawing people in.

Calculated as:
Destination Percentile − Weighted Origin Percentile