Final answer:
GDP represents the total value of all final goods produced within a country. For the given example, despite multiple stages of production, only the value of the final goods, the bookshelves worth $250, is counted towards the nation's GDP. Thus, the GDP of the nation is $250.
Step-by-step explanation:
Gross Domestic Product Calculation
The question at hand involves the calculation of Gross Domestic Product (GDP) for a hypothetical small nation with abundant forests. GDP represents the total value of all final goods and services produced within a country during a specific period, often annually. To calculate this nation's GDP, we consider only the value of final goods to avoid double-counting. This means we take the end products which are not transformed into another product. Given the information, $200 worth of trees were cut down, of which $100 worth was turned into $150 worth of lumber. The final product, $250 worth of bookshelves made from $100 worth of the lumber, is the only value that should be counted towards GDP, as it represents the final good. Therefore, the GDP of the nation is $250.