As nations become wealthier, it is harder for them to sustain high rates of growth. That doesn’t mean that the United States is in decline, or even stagnating. When a nation is as rich as ours, it can realize larger absolute gains than it did in the past and larger gains than other nations even if it has lower growth rates. That’s because a growth rate of, say, 2.5 percent represents a larger increase in absolute wealth the richer an economy becomes. In 1900, a 2.5 percent increase in gross domestic product (GDP) per capita would have translated into about $150 in today’s dollars for every man, woman, and child in the United States. In 2010, it would have been roughly $1,200, reflecting the fact that in the aggregate, we are about eight times wealthier than we were 110 years ago. By focusing too much on growth rates and too little on absolute increases in wealth, we have failed to appreciate the magnitude of economic gains in recent decades.