系列论文:
New Theoretical Perspectives on the Distribution of Income and Wealth among Individuals
Part I. The Wealth Residual
The paper identifies, and then resolves, a number of seeming puzzles in a newly identified set of stylized facts entailing movements in factor returns and shares and the wealth-income ratio. Standard data on savings cannot be reconciled with the increase in the wealth-income ratio: there is a wealth residual. An important component of this is associated with rents: land rents, exploitation rents, and returns on intellectual property.
Nor can these stylized facts be reconciled with a standard neoclassical model, focusing on labor and capital, even taking into account technological change (including skill-biased technological change), with appropriately defined aggregates.
Explaining why the concepts of “capital” and “wealth” are distinct, we show that appropriately defined aggregates for wealth may be (and in the case of some countries appear to be) moving in opposite directions.
We identify some of the factors that may have contributed to the increase in rents and the divergence between wealth and capital. Subsequent Parts of this paper will investigate some of these factors in detail and relate them to changes in inequality.
Part II: Equilibrium Wealth Distributions
This paper investigates the determination of the equilibrium distribution of income and wealth among individuals within a simple equilibrium growth model, where there is consistency between the movements of aggregate variables and the savings, bequest, and reproduction behavior of individuals. It describes centrifugal and centripetal forces, (leading to more or less unequal distributions), identifies the factors that may have contributed to the observed increase in inequality, and provides explicit expressions for the level of tail-inequality in terms of the underlying parameters of the economy and policy variables.
Among the key results are: (i) The magnitude of wealth inequality does not, in general depend on the difference between the rate of interest (r) and the rate of growth (g); the former is itself an endogenous variable that needs to be explained. In the standard generalization of the Solow model, in the long run not only is r < g, but sr < g (where s is the savings rate). (ii) An increase in capital taxation may be (and in some of the central models is) fully shifted, and so may not lead to lower levels of inequality. (iii) If the capital tax is progressive and/or the proceeds go to public investment, wealth inequality may be reduced the well-being of workers may be increased.
Part III: Life Cycle Savings vs. Inherited Savings
This paper extends the standard life cycle model to a world in which there are also capitalists. We obtain simple formulae describing the equilibrium fraction of wealth held by life-cycle savers.
Using these formulae, we ascertain the effects of tax policy or changes in the parameters of the economy. The relative role of life cycle savings increases with the rate of growth and with the relative savings rate of life-cycle savers and capitalists. An increase in the savings rate of workers has no effect on output per capita; life cycle savings simply crowds out inherited savings. A tax on capital (even if proceeds are paid out to workers) is so shifted that capitalists are unaffected and that workers’ income (after transfers) and their share in national wealth are reduced. If the government invests the proceeds, the share of capital owned by life cycle savers may increase.
We extend the analysis to endogenously derive the distribution of the population between life cycle savers and capitalists, in a model in which all individuals have identical non-linear savings functions. When wealth is low enough, bequests drop to zero. With stochastic returns, individuals move between the two groups.
A second extension analyzes the effects of land. We ask whether land holding displaces the holding of capital, resulting in workers being worse off. A tax on land, while reducing the value of land, leaves unchanged the capital-labor ratio, output per capita, and wages. But the tax reduces the aggregate value of wealth, and if the proceeds of the tax are distributed to workers, their income and life cycle savings are increased. On both accounts, wealth inequality is reduced. Thus, consistent with Henry George’s views, a tax on the returns on land, including capital gains, reduces inequality with no adverse effect on national income.
Part IV: Land and Credit
A significant amount of the increase in the wealth income ratio in recent decades is due to an increase in the value of land. We present a series of models that explain why land prices may have increased. These models help us understand the increase in both the wealth income ratio and wealth inequality. One model focuses on certain locations as being positional good. In another, we show that land bubbles are a natural part of market economies, and that on “bubble paths”, wealth may increase, even as the real wealth of the economy diminishes.
Focusing on long run equilibrium, we show that a tax on the returns on land (including capital gains) can lead to higher incomes and less inequality.
We show the links between the increases in land values and the financial system, demonstrating how changes in the rules governing that sector and the conduct of monetary policy may increase inequality.
Given the large amount of life cycle savings, the traditional division of society into the owners of capital and workers or creditors and debtors may no longer provide the most insights for understanding the impact of policies on distribution. The relevant division is between capitalists, who pass on their wealth from generation to generation, and workers, and between the owners of equity and the holders of debt instruments. These distinctions are important for tax, financial and monetary policy. In our simple model, a lowering of interest rates benefits holders of equity— the capitalists—but hurts holders of government bonds, disproportionately life-cycle savers, and thus increases inequality. Similarly, a lowering of collateral requirements or of banks’ capital adequacy requirements does not result in an increase in the overall efficiency of the economy, but leads to more inequality.