A choropleth map colors world countries by their economy classification, using a categorical ordinal color scale. The visualization loads geographic data from the world-atlas TopoJSON and TSV files, then renders the map via d3.geoPath with a natural Earth projection. Zooming is enabled through d3.zoom, and countries highlight red on hover. A custom color legend displays the economy categories as colored circles, while the map also shows a blue sphere background. The code uses d3.scaleOrdinal with schemeSpectral ranges to assign colors.