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Market Size in Innovation: Theory and Evidence from the Pharmaceutical Industry

Quarterly Journal of Economics 2004 119(3), 1049-1090 open access
This paper investigates the effect of (potential) market size on entry of new drugs and pharmaceutical innovation. Focusing on exogenous changes driven by U. S. demographic trends, we find a large effect of potential market size on the entry of nongeneric drugs and new molecular entities. These effects are generally robust to controlling for a variety of supply-side factors and changes in the technology of pharmaceutical research.

Why did the Elites Extend the Suffrage? Democracy and the Scope of Government, with an Application to Britain's "Age of Reform"

Quarterly Journal of Economics 2004 119(2), 707-765
A new rationale is presented for why an elite may want to expand the franchise even in the absence of threats to the established order. Expanding the franchise can turn politicians away from particularistic politics based on ad personam redistribution within the elite and foster competition based on programs with diffuse benefits. If these programs are valuable, a majority of the elite votes in favor of an extension of the franchise despite the absence of a threat from the disenfranchised. We argue that the evolution of public spending and of political competition in nineteenth century Britain is consistent with our model.

Bundling as an Entry Barrier

Quarterly Journal of Economics 2004 119(1), 159-187
In this paper we look at the case for bundHng in an oHgopohstic environment. We show that bundhng is a particularly effective entry-deterrent strategy. A company that has market power in two goods, A and B, can, by bundling them together, make it harder for a rival with only one of these goods to enter the market. Bundling allows an incumbent to credibly defend both products without having to price low in each. The traditional explanation for bundling that economists have given is that it serves as an effective tool of price discrimination by a monopolist. Although price discrimination provides a reason to bundle, the gains are small compared with the gains from the entry-deterrent effect.

Does Local Financial Development Matter?

Quarterly Journal of Economics 2004 119(3), 929-969
We study the effects of differences in local financial development within an integrated financial market. We construct a new indicator of financial development by estimating a regional effect on the probability that, ceteris paribus, a household is shut off from the credit market. By using this indicator, we find that financial development enhances the probability an individual starts his own business, favors entry of new firms, increases competition, and promotes growth. As predicted by theory, these effects are weaker for larger firms, which can more easily raise funds outside of the local area. These effects are present even when we instrument our indicator with the structure of the local banking markets in 1936, which, because of regulatory reasons, affected the supply of credit in the following 50 years. Overall, the results suggest local financial development is an important determinant of the economic success of an area even in an environment where there are no frictions to capital movements.

Choosing How to Choose: Self-Stable Majority Rules and Constitutions

Quarterly Journal of Economics 2004 119(3), 1011-1048
Constitutional arrangements affect the decisions made by a society. We study how this effect leads to preferences of citizens over constitutions; and ultimately how this has a feedback that determines which constitutions can survive in a given society. Constitutions are stylized here, to consist of a voting rule for ordinary business and possibly a different voting rule for making changes to the constitution. We define an equilibrium notion for constitutions, called self-stability, whereby under the rules of a self-stable constitution, the society would not vote to change the constitution. We argue that only self-stable constitutions will endure. We prove that self-stable constitutions always exist, but that most constitutions (even very prominent ones) may not be self-stable for some societies. We show that constitutions where the voting rule used to amend the constitution is the same as the voting rule used for ordinary business are dangerously simplistic, and there are (many) societies for which no such constitution is self-stable. We conclude with a characterization of the set of self-stable constitutions that use majority rule for ordinary business.

How Much Should We Trust Differences-In-Differences Estimates?

Quarterly Journal of Economics 2004 119(1), 249-275 open access
Most papers that employ Differences-in-Differences estimation (DD) use many years of data and focus on serially correlated outcomes but ignore that the resulting standard errors are inconsistent. To illustrate the severity of this issue, we randomly generate placebo laws in state-level data on female wages from the Current Population Survey. For each law, we use OLS to compute the DD estimate of its “effect” as well as the standard error of this estimate. These conventional DD standard errors severely understate the standard deviation of the estimators: we find an “effect” significant at the 5 percent level for up to 45 percent of the placebo interventions. We use Monte Carlo simulations to investigate how well existing methods help solve this problem. Econometric corrections that place a specific parametric form on the time-series process do not perform well. Bootstrap (taking into account the autocorrelation of the data) works well when the number of states is large enough. Two corrections based on asymptotic approximation of the variance-covariance matrix work well for moderate numbers of states and one correction that collapses the time series information into a “pre”- and “post”-period and explicitly takes into account the effective sample size works well even for small numbers of states.

Liquidity and Financial Market Runs

Quarterly Journal of Economics 2004 119(1), 135-158
We model a run on a financial market, in which each risk-neutral investor fears having to liquidate shares after a run, but before prices can recover back to fundamental values. To avoid having to possibly liquidate shares at the marginal postrun price—in which case the risk-averse market-making sector will already hold a lot of share inventory and thus be more reluctant to absorb additional shares—each investor may prefer selling today at the average in-run price, thereby causing the run itself. Liquidity runs and crises are not caused by liquidity shocks per se, but by the fear of future liquidity shocks.

Kidney Exchange

Quarterly Journal of Economics 2004 119(2), 457-488 open access
Most transplanted kidneys are from cadavers, but there are also many transplants from live donors. Recently, there have started to be kidney exchanges involving two donor-patient pairs such that each donor cannot give a kidney to the intended recipient because of immunological incompatibility, but each patient can receive a kidney from the other donor. Exchanges are also made in which a donor-patient pair makes a donation to someone waiting for a cadaver kidney, in return for the patient in the pair receiving high priority for a compatible cadaver kidney when one becomes available. There are stringent legal/ethical constraints on how exchanges can be conducted. We explore how larger scale exchanges of these kinds can be arranged efficiently and incentive compatibly, within existing constraints. The problem resembles some of the “housing” problems studied in the mechanism design literature for indivisible goods, with the novel feature that while live donor kidneys can be assigned simultaneously, cadaver kidneys cannot. In addition to studying the theoretical properties of the proposed kidney exchange, we present simulation results suggesting that the welfare gains from larger scale exchange would be substantial, both in increased number of feasible live donation transplants, and in improved match quality of transplanted kidneys.

Can Labor Regulation Hinder Economic Performance? Evidence from India

Quarterly Journal of Economics 2004 119(1), 91-134
This paper investigates whether the industrial relations climate in Indian states has affected the pattern of manufacturing growth in the period 1958–1992. We show that states which amended the Industrial Disputes Act in a pro-worker direction experienced lowered output, employment, investment, and productivity in registered or formal manufacturing. In contrast, output in unregistered or informal manufacturing increased. Regulating in a pro-worker direction was also associated with increases in urban poverty. This suggests that attempts to redress the balance of power between capital and labor can end up hurting the poor.

Investor Protection, Optimal Incentives, and Economic Growth

Quarterly Journal of Economics 2004 119(3), 1131-1175
Does investor protection foster economic growth? To assess the widely held affirmative view, we introduce investor protection into a standard overlapping generations model of capital accumulation. Better investor protection implies better risk sharing. Because of entrepreneurs' risk aversion, this results in a larger demand for capital. This is the demand effect. A second effect (the supply effect) follows from general equilibrium restrictions. Better protection (i.e., higher demand) increases the interest rate and lowers the income of entrepreneurs, decreasing current savings and next period's supply of capital. The supply effect is stronger the tighter are the restrictions on capital flows. Our model thus predicts that the (positive) effect of investor protection on growth is stronger for countries with lower restrictions. Cross-country data provide support for this prediction, as does the detailed examination of the growth experiences of South Korea and India.