This choropleth map colors countries by economic grouping using a categorical color scale. Users can click legend items to filter the map, dimming non-matching countries while highlighting the selected group. The visualization uses d3.geoNaturalEarth1 and d3.geoPath for map projection, d3.zoom for panning, and d3.scaleOrdinal with schemeSpectral. Country boundaries come from the world-atlas TopoJSON dataset, with hover effects and a tooltip displaying country names and values.