There is a certain absurdity to the obsession with maximizing long-term average income growth in perpetuity, to the neglect of other risks and considerations. Consider a simple thought experiment. Imagine that per capita national income (or some broader measure of welfare) is set to rise by 1% per year over the next couple of centuries. This is roughly the trend per capita growth rate in the advanced world in recent years. With annual income growth of 1%, a generation born 70 years from now will enjoy roughly double today’s average income. Over two centuries, income will grow eight-fold.
Now suppose that we lived in a much faster-growing economy, with per capita income rising at 2% annually. In that case, per capita income would double after only 35 years, and an eight-fold increase would take only a century.
Finally, ask yourself how much you really care if it takes 100, 200, or even 1,000 years for welfare to increase eight-fold. Wouldn’t it make more sense to worry about the long-term sustainability and durability of global growth? Wouldn’t it make more sense to worry whether conflict or global warming might produce a catastrophe that derails society for centuries or more?