Paul Krugman was awarded the 2008 Nobel Memorial Prize in Economics for his work developing new trade theory (NTT) and new economic geography (NEG). NTT introduced the idea that countries can trade similar goods if they produce different brands, allowing for increasing returns to scale and consumer preference for variety. NEG built on NTT, explaining that successful countries will see production concentrate in dense, high-income regions and cities. Krugman's work provided new insights into why countries trade and how economic activity locates spatially.