This choropleth map displays global economic classifications by country, with an interactive legend that filters the map to highlight a selected category while dimming others. The visualization uses a natural Earth projection via `d3.geoNaturalEarth1` and renders country paths with `d3.geoPath` in an SVG. Users can click legend circles to toggle filtering, and a zoom behavior (`d3.zoom`) enables panning and scaling. Data comes from the World Atlas TopoJSON and TSV files, with colors mapped using `d3.scaleOrdinal` and `schemeSpectral`.