Knowledge that Transforms

Common currencies affect trading costs and, thereby, the amounts of trade, output, and consumption. From the perspective of monetary policy, the adoption of another country's currency trades off the benefits of commitment to price stability (if a committed anchor is selected) against the loss of an independent stabilization policy. We show that the type of country that has more to gain from giving up its own currency is a small open economy heavily trading with one particular large partner, with a history of high inflation and with a business cycle highly correlated with that of the potential “anchor.” We also characterize the features of the optimal number of currency unions.

This paper investigates individual motives to participate in rotating savings and credit associations (roscas). Detailed evidence from roscas in a Kenyan slum (Nairobi) suggests that most roscas are predominantly composed of women, particularly those living in a couple and earning an independent income. We propose an explanation of this based on conflictual interactions within the household. Participation in a rosea is a strategy a wife employs to protect her savings against claims by her husband for immediate consumption. The empirical implications of the model are then tested using the data collected in Kenya.

We show that even in the absence of diminishing returns in production and technological spillovers, international trade leads to a stable world income distribution. This is because specialization and trade introduce de facto diminishing returns: countries that accumulate capital faster than average experience declining export prices, depressing the rate of return to capital and discouraging further accumulation. Because of constant returns to capital accumulation from a global perspective, the world growth rate is determined by policies, savings, and technologies, as in endogenous growth models. Because of diminishing returns to capital accumulation at the country level, the cross-sectional behavior of the world economy is similar to that of existing exogenous growth models: cross-country variation in economic policies, savings, and technology translate into crosscountry variation in incomes. The dispersion of the world income distribution is determined by the forces that shape the strength of the terms-of-trade effects— the degree of openness to international trade and the extent of specialization.

Estimates of the effect of college selectivity on earnings may be biased because elite colleges admit students, in part, based on characteristics that are related to future earnings. We matched students who applied to, and were accepted by, similar colleges to try to eliminate this bias. Using the College and Beyond data set and National Longitudinal Survey of the High School Class of 1972, we find that students who attended more selective colleges earned about the same as students of seemingly comparable ability who attended less selective schools. Children from low-income families, however, earned more if they attended selective colleges.

This paper investigates the optimal income transfer problem at the low end of the income distribution. The government maximizes a social welfare function and faces the traditional equity-efficiency trade-off. The paper models labor supply behavioral responses along the intensive margin (hours or intensity of work on the job) and along the extensive margin (participation in the labor force). Optimal tax formulas are derived as a function of the behavioral elasticities, the shape of the income distribution and the redistribution tastes of the government. When behavioral responses are concentrated along the intensive margin, the optimal transfer program is a classical Negative Income Tax program with a substantial guaranteed income support that is taxed away at high rates. However, when behavioral responses are concentrated along the extensive margin, the optimal transfer program is an Earned Income Credit program with negative marginal tax rates at low income levels and a small guaranteed income. Numerical simulations calibrated with the actual empirical earnings distribution are presented for a range of behavioral elasticities and redistributive tastes of the government. For realistic elasticities, the optimal program provides a moderate guaranteed income, imposes low tax rates on very low annual earnings levels, and then starts phasing out

This paper argues that parties regulate competition among Hke-minded factions so as to enhance reputation building by, and voter trust in, the politicians standing for a given cause. While intra- and interparty competition contributes to keeping politicians on their toes, unbridled competition may encourage politicians to challenge good platforms and to wage competition along socially suboptimal dimensions (for example, by privileging form over content). The paper builds a simple model of intraparty competition and studies whether various hierarchical or democratic party institutions constitute an efficient form of party governance. The paper shows that intraparty disagreements, when they occur, hurt the party's position in the general election, but that their possibility enhances party image; and that parties must be able to avoid behind-the-scene allocations of portfolios and spoils in order to be credible. Last, it analyzes the impact of political polarization and interparty competition on the choice of party governance.

This paper analyzes monotone comparative statics predictions in several classes of stochastic optimization problems. The main results characterize necessary and sufficient conditions for comparative statics predictions to hold based on properties of primitive functions, that is, utility functions and probability distributions. The results apply when the primitives satisfy one of the following two properties: (i) a single-crossing property, which arises in applications such as portfolio investment problems and auctions, or (ii) log-supermodularity, which arises in the analysis of demand functions, affiliated random variables, stochastic orders, and orders over risk aversion.

We study the effects of electoral institutions on the size and composition of public expenditure in OECD and Latin American countries. We emphasize the distinction between purchases of goods and services, which are easier to target geographically, and transfers, which are easier to target across social groups. We present a theoretical model in which voters anticipating government policymaking under different electoral systems have an incentive to elect representatives more prone to transfer (public good) spending in proportional (majoritarian) systems. The model also predicts higher total primary spending in proportional (majoritarian) systems when the share of transfer spending is high (low). After defining rigorous measures of proportionality to be used in the empirical investigation, we find considerable support for our predictions.

In order to investigate the impact of limited memory on human behavior, I develop a model of memory grounded in psychological and biological research. I assume that people take their memories as accurate and use them to make inferences. The resulting model predicts both over- and underreaction but provides enough structure to predict when each effect dominates. I then use this framework to study the consumption decision. The results match empirical work on consumption predictability as well as differences in the marginal propensity to consume from different income streams. Most importantly, because it ties the extent of bias to a measurable aspect of the stochastic process being forecasted, the model makes testable empirical predictions.

To quantify the implications of common currencies for trade and income, we use data for over 200 countries and dependencies. In our two-stage approach, estimates at the first stage suggest that belonging to a currency union/board triples trade with other currency union members. Moreover, there is no evidence of trade-diversion. Our estimates at the second stage suggest that every one percent increase in a country’s overall trade (relative to GDP) raises income per capita by at least one third of a percent. We combine the two estimates to quantify the effect of common currencies on output. Our results support the hypothesis that important beneficial effects of currency unions come through the promotion of trade.