A world map rendered as a choropleth uses color to encode each country’s economy classification. Built with D3 v5 and topojson, the visualization loads geographic data from a 50m world-atlas JSON and TSV files, then projects it using `geoNaturalEarth1`. The `scaleOrdinal` color scale applies the `schemeSpectral` palette, while a custom legend displays the categories. Hovering turns a country red, and zooming is supported via the `zoom` event handler.