A phased increase in the U.S. investment rate: Sacrifice times, T-year gains, and investment rate returns

We simulate a phased increase in the U.S. investment rate using a translog production function with technical progress (disembodied and/or embodied). We assume there will be an absorption lag implying that factors are underutilized during the transition to a higher investment rate. We find that the “sacrifice time” (the time that elapses until consumption surpasses the value it would have had under the initial investment rate) is roughly nine years. Across alternative specifications, phase-in periods, and absorption lags, the sacrifice time varies from seven to 13 years, and is insensitive to the percentage increase in the investment rate. With a three-year phase-in of a 20 percent increase in the investment rate with a one-year absorption lag, the average “ecade gain” in output (the percentage gain at the end of a decade) is roughly 4 percent; the decade gain in consumption, 0 percent; the five-decade gain, 10 percent in output and 6 percent in consumption; and the “investment rate return” (the internal rate of return on a permanent increase in the investment rate), 13 percent.