	Introduction

The rate of long-term economic growth is the salient measure of the nation's ability to steadily advance its material living standard. The pace of long-term economic growth is likely to be a central focus of attention in the decades just ahead, as the U.S. economy must confront the need to undertake unprecedentedly large generational transfers of income to pay for the retirement of the huge baby-boom generation. Although the trend growth rates of mature industrial economies have historically not shown great variability, even relatively small differences in that growth rate steadily cumulate to have sizeable effects on the scale of improvement in future living standards. For the United States, the long-term growth of real GDP per capita over the last 125 years has revealed remarkable steadiness, advancing decade after decade with only modest and temporary variation from the observed 1.8% annual rate of increase. Overall, the limited variability of the rate of U.S. long-term growth over such a long time period, despite major changes in economic conditions, as well as economic and social polices, suggests that U.S. long-term growth may be governed by forces other than typical economic variables and may not be easy to deliberately alter with conventional economic policies. Nevertheless, the evidence of some degree of medium-term variability suggests the possibility of using economic policy to exert some influence. as well as cognitive skills. Given this supporting infrastructure, economic theory and evidence make it reasonably clear that countries that have achieved sustained long-term growth such as the United States are those that invest a sizable fraction of current income in the accumulation of physical and human capital and have accumulated large stocks of both. More importantly, they are also economies that have been able to steadily raise the productivity of these two inputs through a steady advance of technical knowledge. There are reasons to believe, despite its evident economic success, that the United States, due to varying degrees of market failure, may under invest in each of the three basic determinants of economic growth. In theory, correcting that under investment through some form of government intervention could lead to an optimal increase in the rate of accumulation of each determinant, and through that an acceleration of the economy's rate of economic growth. Knowing that there is the potential for improving on certain market outcomes is one thing. Designing economic policies that will efficiently induce these improvements is another thing. The information shortcoming about what, where, and how much to invest that the policymaker would have to contend with will often be substantial, and greatly raise the risk that the policy will be so blunt and misdirected that it generates more economic costs than benefits.
The rate of long-term economic growth is the salient measure of the nation's ability to steadily advance its material living standard. The pace of long-term economic growth is likely to be a center of attention in the decades just ahead, as the U.S. economy confronts the need to undertake unprecedentedly large generational transfers of income to pay for the retirement of the huge baby-boom generation as well as large transfers to the rest of the world to meet the debt service costs of the United States' large and still growing foreign debt.
For the United States, the long-term growth of real GDP per-capita over the last 125 years has revealed remarkable steadiness, advancing decade after decade with only modest and temporary variation from a trend annual average rate of growth of 1.8%. Overall, the limited variability of the rate of U.S. long-term growth, despite major changes in economic conditions, as well as economic and social policies, suggests that U.S. long-term growth may be governed by forces other than typical economic variables and may not be easy to alter with conventional economic policy. Nevertheless, the evidence of some degree of medium-term variability suggests the possibility of using economic policy to exert some influence. It is important to recognize that even relatively small differences in the rate of economic growth will steadily cumulate to have large effects on the scale of improvement in future living standards. Such an improvement would make the burden of future transfers on workers less onerous.
Given a supporting social infrastructure that encourages and enables production of goods and services, economic theory and evidence make it reasonably clear that countries that have achieved sustained long-term growth such as the United States are those that invest a sizable fraction of current income in the accumulation of physical and human capital and have and continue to accumulate large stocks of both. As importantly, they are also economies that have been able to steadily raise the productivity of these two inputs through a steady advance of technical knowledge. There are reasons to believe, despite its evident economic success, that the United States, due to varying degrees of market failure, may under invest in each of the three determinants of economic growth. In theory, correcting that under investment through some form of government intervention could lead to an optimal increase in the rate of accumulation of each determinant, and through that to an acceleration of the economy's rate of economic growth. Knowing that there is the potential for improving on certain market outcomes is one thing. Designing economic policies that will efficiently induce these improvements is another thing. The information shortcoming about what, where, and how much to invest with which the policymaker would have to contend will often be substantial, and greatly raises the risk that the policy will be so blunt and misdirected that it will generate more economic costs than benefits.
This report will be updated annually.