David McCandless Data Visualization Bubble Chart Infographic

Data visualization infographic titled "Choropleth Map Example" using a BUBBLE CHART as the dominant visual element, specifically a clean pseudo-3D scatter / bubble chart that shows contrast across illustrative regions. X-axis label in English: "Population Density (people per km²)" with sharp tick marks from 0 to 1,000. Y-axis label in English: "Median Income (USD, illustrative)" with sharp tick marks from 0 to 100,000. Z dimension expressed by bubble size label in legend: "CO2 Emissions per Capita (tons, illustrative)". Optional grayscale depth cue only, no distorted perspective, no misleading scale manipulation, no truncated axes. Plot 10-14 labeled illustrative regions such as "Region A", "Region B", "Region C", "Region D", showing strong contrast clusters: dense-low income-small emissions, dense-high income-medium emissions, sparse-high income-large emissions, mid-density-mid income-mixed emissions. Include a subtle side mini-panel titled "Why this is not a choropleth" that contrasts map-based shading versus bubble-position encoding, with a tiny grayscale map icon and scatter icon, but keep the bubble chart dominant.

Add 4 key insight callouts with small icons and concise English text: 1) headline number "3.4x" with interpretation "Highest-income cluster earns 3.4x more than the lowest-income cluster" and a small income / coin icon. 2) headline number "820" with interpretation "Densest illustrative region reaches 820 people per km²" and a small city / buildings icon. 3) headline number "18.6" with interpretation "Largest bubble shows the highest emissions intensity at 18.6 tons per capita" and a small cloud / emissions icon. 4) headline number "2 clusters" with interpretation "Two distinct groups reveal the strongest contrast in density and income" and a small contrast / split icon.

Use realistic plausible numbers only, clearly marked where needed as illustrative. All labels must be in English and explicitly rendered as: chart title "Choropleth Map Example", subtitle "Illustrative bubble chart showing contrast across regions", legend title "Bubble Size: CO2 Emissions per Capita (illustrative)", callout tag "Key Insights", annotation labels such as "High density, lower income" and "Low density, higher income". Add clean region labels near points, for example: "Region A", "Region B", "Region C", "Region D". Include a small source / data-note strip at the bottom reading exactly: "Data note: Illustrative example for layout demonstration. Figures are not sourced real-world values." 

Visual style: editorial data journalism illustration, FT / Bloomberg-grade chart aesthetics, vector-clean infographic layout. Monochrome ink palette only: black, charcoal, soft gray, off-white background, subtle dot-grid or fine ruled-paper texture, crisp hairlines, restrained shading, elegant newsroom mood, analytical and high-contrast. Strong typography hierarchy, ample whitespace, precise legend, neat axis ticks, balanced annotations, minimalist icons, no decorative clutter. Include subtle visual storytelling cues that emphasize contrast between clusters.

All text MUST be written in English (array). Every heading, label, caption, legend and metric name in the image must be in English — not English. Spell each English word correctly using English characters and diacritics. Numbers stay as digits, no fake authoritative sources cited, no watermarks Numbers labeled "illustrative" unless the user supplied specific sourced data. No fake authoritative sources cited (do not invent "Source: Reuters 2025" — use "Illustrative example" instead). No misleading axis truncation or scale manipulation.