Income, income inequality, and health: Evidence from China

This paper tests using survey data from China whether individual health is associated with income and community-level income inequality. Although poor health and high inequality are key features of many developing countries, most of the earlier literature has drawn on data from developed countries in studying the association between the two. We find that self-reported health status increases with per capita income, but at a decreasing rate. Controlling for per capita income, we find an inverted-U association between self-reported health status and income inequality, which suggests that high inequality in a community poses threats to health. We also find that high inequality increases the probability of health-compromising behavior such as smoking and alcohol consumption. Most of our findings are robust to different measures of health status and income inequality. Journal of Comparative Economics 34 (4) (2006) 668–693.     

Zero-sum condition: A necessary and sufficient condition for a transitive voting system

A simple and quick way to ascertain whether or not any given majority voting system can always produce a transitive social preference orderings without imposing any restriction on the distribution of diverse individual preference orderings is to examine whether all individual voting (preference) vectors satisfy the Addition Rule or not. This conclusion was obtained by first reformulating the voting mechanism into that of a linear mapping from T^m defined by q = Σp_i. It was found that the subset P of T that can accommodate all possible individual preference ordering profiles and such that every sum vector q = Σ p_i of its member vectors p_i is contained in T can be expressed as P = {p: p∈ T, s(p) = 0}. It was also pointed out that this is equivalent to the requirement that all individual preference (voting) functions must satisfy the Addition Rule. Finally, Borda's Rule and Saposnik's Contributive Rule were shown to be examples of transitive voting rules which satisfy these necessary and sufficient conditions.     

Equality of opportunity and educational achievement in Portugal

Portugal has one of the highest levels of income inequality in Europe, and low wages and unemployment are concentrated among low skill individuals. Education is an important determinant of inequality. However, there are large differences in the educational attainment of different individuals in the population, and the sources of these differences emerge early in the life-cycle when families play a central role in individual development. We estimate that most of the variance of school achievement at age 15 is explained by family characteristics. Observed school inputs explain very little of adolescent performance. Children from highly educated parents benefit of rich cultural environments in the home and become highly educated adults. Education policy needs to be innovative: (1) it needs to explicitly recognize the fundamental long run role of families on child development; (2) it needs to acknowledge the failure of traditional input based policies.

Advances in Inequality Measurement and Usefulness of Statistical Inference

Assessment of inequality measurement is the focus for this survey. All measures of inequality must be evaluated based on a set of desirable properties. More importantly, the usefulness of statistical inference for measures of inequality needs examination.

Exact aggregation and Generalized Slutsky Conditions

This article indicates a natural connection between Generalized Slutsky Conditions and demand structures of the exact aggregation form. It is shown that Generalized Slutsky Conditions are assured when the number of consumers is greater than or equal to the number of goods, if and only if demands are of a generalized exact aggregation form. This result provides some understanding of the properties of aggregate demand and allowable differences between consumers, as well as naturally generalizing W. M. Gorman's (Econometrica21 (1953), 63–80) famous conditions for the integrability of aggregate demand.     

The inequality–growth nexus in the short and long run: Empirical evidence from China

This paper argues that the conventional approach of data averaging is problematic for exploring the growth–inequality nexus. It introduces the polynomial inverse lag (PIL) framework so that the impacts of inequality on investment, education, and ultimately on growth can be measured at precisely defined time lags. Combining PIL with simultaneous systems of equations, we analyze the growth–inequality relationship in postreform China, finding that this relationship is nonlinear and is negative irrespective of time horizons. Journal of Comparative Economics 34 (4) (2006) 654–667.     

Mutual Insurance,Individual Savings,and Limited Commitment

We examine a dynamic model of mutual insurance when households can also engage in self-insurance by storage. We assume that there is no enforcement mechanism, so that any insurance is informal and must be self-enforcing. We show that consumption allocations satisfy a modified Euler condition and that an enhanced storage technology can either improve or diminish welfare. Furthermore we show that the ex ante transfers introduced into dynamic informal insurance models recently by Gauthier et al. (Gauthier, C., Poitevin, M., and González, P. (1997). Journal of Economic Theory76, 106–144) are only used here in the first period, with the role of ex ante transfers being replaced by differential individual storage. Journal of Economic Literature Classification Numbers: C61, C73, D90, E21.     

Aggregation for material balances

In an input-output system, let final demands and gross outputs be iteratively balanced by successive approximations. The speed of convergence will depend, among other things, on the initial choice of gross outputs. Suppose that, using some aggregation weights, aggregate supply is made equal to aggregate demand in the initial plan. The current paper finds the set of aggregation weights that yields speediest convergence. An economic interpretation of the “optimal” aggregation weights is given, and some examples are calculated. J. Comp. Econ., March 1978, 2(1), pp. 1–11. Boston University, Boston, Mass., and Massachusetts Institute of Technology, Cambridge, Mass.     

Credit constraints,growth and inequality dynamics

This paper examines how credit constraints affect the dynamics of wealth and thereby the dynamics of capital and output growth. We develop standard Ak growth models that display transitional dynamics, contrary to general belief, once the complete credit markets assumption is relaxed. The mechanism is that credit constraints make individual productivity differences persist, which in turn leads to the persistence of income inequality. The dynamics of inequality is jointly determined with the dynamics of aggregate capital. The economy thus passes through a transitional period of inequality, individual and aggregate capital dynamics before it converges to a long-run balanced growth path. The application of the model to the analysis of intergenerational mobility and inequality dynamics suggests substantial economic and policy significance. In particular, introducing credit constraints to the Barro Ak model, public investment could have an indirect impact on growth via its effect on inequality and mobility.     

Spain is different: Falling trends of inequality

In this article we characterize the evolution of inequality in hourly wages, hours of work, labor earnings, household disposable income and household consumption for Spain between 1985 and 2000. We look at both the Encuesta Continua de Presupuestos Familiares and the European Household Community Panel. Our analysis shows that inequality in individual net labor earnings and household net disposable income has decreased substantially. The decreases in the tertiary education premium and in the unemployment rate have been key ingredients to understand this falling trend. Public transfers have played a crucial role in smoothing out the inequality arising in the labor market, but instead the Spanish family does not seem to have been an important insurance mechanism. Regarding household consumption, inequality has fallen much less than inequality in household net disposable income, with the decrease mostly concentrated in the second half of the eighties. This suggests that the reduction in income inequality has affected the sources of permanent differences between households only during the second half of the eighties. Our estimates of the earnings process for the period are consistent with this view.     

Aggregation and the existence of a social utility function

In a well-known paper Gorman (Econometrica21 (1953)) established that the necessary and sufficient condition for the existence of an aggregate, or social, utility function, independent of the distribution of income, is that all individuals' income consumption paths be parallel straight lines. Recently Chipman (J. Econ. Theory8 (1974)), building on the paper of Hurwicz and Uzawa (in “Preference Utility and Demand”) has shown that if the distribution of income is proportional and individual preferences are homothetic, aggregate consumption behavior obeys the necessary integrability conditions. It is shown here that the consistency of aggregate behavior can be derived from more general conditions than the ones used by Chipman and Gorman. Examples of demand systems from which aggregate behavior implies a social utility function are provided. It is then shown that if individual demand functions are linear in income—a form employed by both Gorman and Chipman—it is not necessary that the distribution of income be fixed.     

The finite basis property and exact aggregation

An individual demand function is said to satisfy the finite basis property when its set of Engel curves has a finite spanning subset. In the present letter we discuss why this property underlies the theory of exact aggregation.     

Jensen’s Inequality in Finance

The purpose of this paper is to measure the size and the statistical significance of three inequalities in the field of financial economics. The three are variants of Jensen’s inequality. The first inequality is a comparison of the expected value of a ratio to the ratio of the expected value, a problem that arises in pricing foreign exchange rates. The second is a comparison of the log of the expected value to the expected value of the log, a problem that arises in testing forward market efficiency, money demand, production functions, and trade gravity models. The third is a comparison of the expected utility to the utility of the expected value, and helps in determining the importance of the expected utility paradigm, and the magnitude of the equity risk premium. The methodology used is by simulation of random normal variables, thereby introducing sampling error. Despite this sampling error the conclusion is general: all three inequalities are economically material, and stand statistically as inequalities. The major conclusion is that Jensen’s inequality is not a theoretical and superfluous exercise in finance as some have advocated.

On equilibrium in Hart's securities exchange model

In this paper, we use a no unbounded arbitrage condition to give a very direct proof of the existence of equilibrium in Hart's unbounded securities exchange model (J. Econ. Theory, 9 (1974), 293–311). We also examine the relationship between the no unbounded arbitrage condition and the sufficiency conditions of Hart, ibid. and Hammond (J, Econ. Theory, 31 (1983), 170–175). We present an example to show that if traders are not sufficiently risk averse, then Hammond's overlapping expectations condition is not, in general, equivalent to the no unbounded arbitrage condition or Hart's sufficiency conditions, and therefore, is not sufficient to guarantee the existence of equilibrium. We also present an example to show that it is possible for the no unbounded arbitrage condition to hold without overlapping expectations, and therefore, it is possible for equilibrium to exist without overlapping expectations.     

On least squares estimation with a particular linear function of the dependent variable

We consider the standard linear regression model where the endogenous variable y is substituted by Ty, T being a symmetric, idempotent matrix. Comparing the mean square error (MSE) matrices we show that a ‘naive’ LS-procedure may work better than a competing estimator usually proposed in the literature and may even perform better than the LS-estimator based on untransformed data. We derive necessary and sufficient conditions for MSE-dominance and outline some ideas for testing.     

Aggregation bias-correcting approach to the health–income relationship: Life expectancy and GDP per capita in 148 countries, 1970–2010

A large amount of data consisting of 148 countries for the years 1970 to 2010 is analysed in the context of the health–income relationship. The literature suggests that the biased income–health effect obtained with macro data can be a result of the aggregation of individual concave income functions on average health. This aggregation problem is analysed in detail, and a bias-correcting method is proposed to overcome it. The results with new model alternatives show that they correct the income effects on average health in the right direction; that is, they produce smaller parameter estimates than biased models. Augmenting the results with the quantile regression approach, which is sensitive to health differences between countries, indicates that the poorest countries’ income gradient is still much larger than that of rich countries. However, the median life expectancy effect of the log of GDP per capita across the countries decreased during the sample decennials. The results for income inequality measured with the Gini coefficient indicate that the effects of inequality on health are still significant in the poorest countries but non-significant among rich countries after the year 2000. We argue that the proposed bias-correcting method retains the interest in macro health modelling and offers new model alternatives in other contexts.     

Rural Industrialization and Increasing Inequality: Emerging Patterns in China′s Reforming Economy

This paper′s goal is to increase the understanding of the inequality trends during the postreform period in China. It uses a rigorous, inference-based procedure to demonstrate that inequality among the counties in an east coast province registered statistically significant increases between 1984 and 1989. Decomposition analysis reveals that the changing patterns of inequality were closely associated with the changes in the structure of the rural economy. In particular, policies that increased the importance of agriculture in the economy led to a reduction in inequality; those that stimulated the expansion of rural industry gave rise to greater inequality. One explanation is that barriers keep outputs, inputs, and information from flowing among regions, leading to higher inequality. J. Comp. Econom., December 1994, 19(3), pp. 362-391. Food Research Institute, Stanford University, Stanford, California 94305-6084.     

Do the best go west? An analysis of the self-selection of employed East-West migrants in Germany

Since the inequality of earnings in East Germany has approached West German levels in the late 1990s, the standard Roy model predicts that a positive selection bias of East-West migrants should disappear. Using a switching regression model and data from the IAB-employment sample, we find however that employed East-West migrants remain positively self-selected with respect to unobserved abilities. This result is consistent with the predictions of our extended Roy model which considers moving costs that are negatively correlated with labour market abilities of individuals. Moreover, we find that wage differentials as well as differences in employment opportunities are the central forces which drive East-West migration after unification.

Efficiency,incentives, and individual labor supply in the labor-managed firm

Parallels are drawn between the approach to the theory of individual labor supply used by Sen (“Labor Allocation in a Co-operative Enterprise.” Rev. Econ. Stud.33: 361–371, Oct. 1966) and approaches of more recent contributions. The paper considers questions of comparative statics in a general model and attempts to distinguish between behavior in labor-managed firms and profit-maximizing firms. Diagrammatic analysis is used for a simple case where income effects are absent. Questions of efficiency and comparative statics are studied in the short run (membership fixed) and in the medium term (membership variable). Finally an incentive scheme to promote efficiency is described.     

Core allocations and the dimension of the cone of efficiency price vectors

Let (R₁,…,R_k) be an arbitrary partition of the grand coalition in an atomless exchange economy with k “large enough.” We prove that an optimal allocation x belongs to the core if and only if x cannot be improved upon by any coalition that includes at least one of the R_i's. K is “large enough” if k ? r + 1, where r is the linear dimension of the cone P of the efficiency price vectors for x. Recall that it is always true that r ? n, when n is the number of commodities in the market, and that under differentiability and interiority r = 1; thus k can be chosen to be 2 (i.e., for any coalition R, an allocation x belongs to the core of the market if and only if x is not blocked by any coalition that either contains R or contains its complement).