Computation of equilibria in heterogeneous agent models

This paper essentially puts together procedures that are used in the computation of equilibria in models with a very large number of heterogeneous agents. It is not a complete description of all procedures used in the literature. It describes procedures that deal with infinitely lived agent versions of the growth model with and without aggregate uncertainty, overlapping generations models, and dynamic political economy models.Econometric models

The Balance of Payments and Borrowing Constraints: An Alternative View of the Mexican Crisis

In standard models of the balance of payments, crises occur when investors begin to doubt the credibility of the government's commitment to its exchange rate policy. In this paper, we develop an alternative model in which balance of payments crises occur even if the credibility of government fiscal, monetary, and exchange rate policies is never in doubt. In this alternative model, international lending is constrained by the risk of repudiation. Balance of payments crises occur when the government and citizens of a country hit their international borrowing constraints. Our model is broadly consistent with events in Mexico from 1987-1995. More generally, our model suggests that countries which undertake sweeping macroeconomic and structural reforms should expect to face a balance of payments crisis when they exhaust their access to international capital inflows.

The balance of payments and borrowing constraints: an alternative view of the Mexican crisis

In this paper we develop a model in which a country faces a balance of payments crisis if constraints on its international borrowing bind. We use the model to describe the dynamics of the trade balance, capital account, and balance of payments of a country that borrows to finance consumption following sweeping macroeconomic and structural reforms and then hits constraints on its international borrowing. We compare the predictions of this theoretical example with events in Mexico from 1987 through 1995.Financial crises - Mexico ; Balance of payments ; Mexico

Life insurance and household consumption.

In this paper, we use data of life insurance holdings by age, sex, and marital status to infer how individuals value consumption in different demographic stages. Essentially, we use revealed preference to estimate equivalence scales and altruism simultaneously in the context of a fully specified model with agents facing U.S. demographic features and with access to savings markets and life insurance markets. Our findings indicate that individuals are very caring for their dependents, that there are large economies of scale in consumption, that children are costly but wives with children produce a lot of goods in the home and that while females seem to have some form of habits created by marriage, men do not. These findings contrast sharply with the standard notions of equivalence scales.Insurance

On the equilibrium concept for overlapping generations organizations

A necessary feature for equilibrium is that beliefs about the behavior of other agents are rational. We argue that in stationary OLG environments this implies that any future generation in the same situation as the initial generation must do as well as the initial generation did in that situation. We conclude that the existing equilibrium concepts in the literature do not satisfy this condition. We then propose an alternative equilibrium concept, organizational equilibrium, that satisfies this condition. We show that equilibrium exists, it is unique, and it improves over autarky without achieving optimality. Moreover, the equilibrium can be readily found by solving a maximization program.Economics ; Equilibrium (Economics) - Mathematical models

Finite-Life, Private-Information Theory of Unsecured Debt

We propose a theory of unsecured debt that is based on the existence of private information about a person's type and on the fact that some debtors have the incentive to forego bankruptcy in order to signal their type. The theory formalizes the idea that the type of a person is relevant to trading partners in many exchange situations and by resisting opportunistic behavior in one exchange context, a person may signal valuable information about his type to trading partners in other exchange contexts. In the model, by resisting opportunistic behavior in the credit market borrowers can signal their type to the insurance market. The model is consistent with the observation that insurers use credit scores to predict the likelihood of a person filing insurance claims.Adverse Selection, Insurance, Credit Scores, Default Risk

Financial Integration, Financial Deepness and Global Imbalances

Large and persistent global financial imbalances need not be the harbinger of a world financial crash. Instead, we show that these imbalances can be the outcome of financial integration when countries differ in financial markets deepness. In particular, countries with more advanced financial markets accumulate foreign liabilities in a gradual, long-lasting process. Differences in financial deepness also affect the composition of foreign portfolios: countries with negative net foreign asset positions maintain positive net holdings of non-diversifiable equity and FDI. Abstracting from the potential impact of globalization on financial development, liberalization leads to sizable welfare gains for the more financially-developed countries and losses for the others. Three empirical observations motivate our analysis: (1)financial deepness varies widely even amongst industrial countries, with the United States ranking at the top; (2) the secular decline in the U.S. net foreign asset position started in the early 1980s, together with a gradual process of international capital markets liberalization; (3) net exports and current account balances are negatively correlated with indicators of financial development.

Marital risk and capital accumulation

Between the sixties and the late eighties the percentages of low-saving single-parent households and people living alone have grown dramatically at the expense of high-saving married households, while the household saving rate has declined equally dramatically. A preliminary analysis of population composition and savings by household type seems to indicate that about half of the decline in savings is due to demographic change. We construct a model with agents changing marital status, but where the saving behavior of the households can adjust to the properties of the demographic process. We find that the demographic changes that reduce the number of married households (mainly higher divorce and higher illegitimacy) induce all household types to save more and that the effect on the aggregate saving rate is minuscule. We conclude that the drop in savings since the sixties is not due to changes in household composition.Saving and investment

A quantitative theory of unsecured consumer credit with risk of default

The authors study, theoretically and quantitatively, the general equilibrium of an economy in which households smooth consumption by means of both a riskless asset and unsecured loans with the option to default. The default option resembles a bankruptcy filing under Chapter 7 of the U.S. Bankruptcy Code. Competitive financial intermediaries offer a menu of loan sizes and interest rates wherein each loan makes zero profits. They prove the existence of a steady-state equilibrium and characterize the circumstances under which a household defaults on its loans. They show that their model accounts for the main statistics regarding bankruptcy and unsecured credit while matching key macroeconomic aggregates and the earnings and wealth distributions. They use this model to address the implications of a recent policy change that introduces a form of “means-testing” for households contemplating a Chapter 7 bankruptcy filing. They find that this policy change yields large welfare gains. ; Also issued as Payment Cards Center Discussion Paper No. 07-08, 05-12, and 01-01 ; Supersedes Working Paper No. 05-18 and 02-6Consumer credit ; Risk ; Default (Finance)

Constrained efficiency in the neoclassical growth model with uninsurable idiosyncratic shocks

We investigate the welfare properties of the one-sector neoclassic growth model with uninsurable idiosyncratic shocks. We focus on the constrained efficiency notion of the general equilibrium literature, and we demonstrate constrained inefficiency for our model. We provide a characterization of constrained efficiency that uses the first-order condition of a constrained planner's problem that points to the margins of relevance for whether capital is too high or too low: the income composition of the (consumption-)poor. We calibrate our benchmark model parameters governing idiosyncratic risks to the U.S. earnings and wealth distribution, and for this distribution the income of the poor is mainly composed of labor earnings. We compute the constrained-efficient allocations - including transition dynamics - for our model economy, and we conclude that the long-run capital stock in a laissez-faire world is not only too low, but much too low. We also show that one can find parameterizations with different qualitative features: in one case, the steady-state capital stock is too high, and in another case no steady state exists.Constrained efficiency, idiosyncratic risks, neoclassical growth model