Step 1: Identify the exact award year and category → The question is about the Nobel Prize in Economic Sciences for 2018. Step 2: Clarify the formal title → This prize is formally called “The Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel”, awarded by the Royal Swedish Academy of Sciences. Step 3: Recall the 2018 laureates → In 2018, two individuals were awarded: William D. Nordhaus and Paul M. Romer. Step 4: Note their contributions → William Nordhaus was honored for integrating climate change into long-term macroeconomic analysis; Paul Romer was recognized for integrating technological innovation into long-term macroeconomic analysis. Step 5: Count the number of awardees → Since two distinct persons received the award in 2018, the total number is 2. Step 6: Cross-check with Nobel trends → It is common for the Economics prize to be shared between two or three people; 2018 was specifically a two-person year. Step 7: Apply formatting rule → The question instructs that the answer must not include spaces; the digit “2” already meets this condition. Final Answer: 2