Score manipulation,density continuity and intent-to-treat effect for regression discontinuity

Regression discontinuity (RD) is widely used in many disciplines of science to find treatment effect when the treatment is determined by an underlying running variable (‘score') crossing a cutoff or not. The main attraction of RD is local randomization around , which is, however, often ruined by manipulation on . To detect manipulation, the continuity of score density function at is routinely tested in practice. In this paper, we examine how informative is for RD, and show the following. First, for incumbency effect in election to which RD has been heavily applied, may have no information content. Second, for RD in general, the continuity is neither necessary nor sufficient for RD validity. Third, if the treatment cannot be implemented without manipulation of , then the manipulation had better be considered as part of the treatment effect, much as in ‘intent-to-treat effect’ for clinical trials. These findings call for relying less on continuity tests and, instead, thinking more about how subjects react to the treatment to modify their , how to design the treatment to lessen manipulation, and what to take as the desired treatment effect.     

Unit Root Tests for Dependent Micropanels

This paper proposes a new test for the null hypothesis of panel unit roots for micropanels with short time dimensions (T) and large cross‐sections (N). There are several distinctive features of this test. First, the test is based on a panel AR(1) model allowing for cross‐sectional dependency, which is introduced by a factor structure of the initial condition. Second, the test employs the panel AR(1) model with AR(1) coefficients that are heterogeneous for finite N. Third, the test can be used both for the alternative hypothesis of stationarity and for that of explosive roots. Fourth, the test does not use the AR(1) coefficient estimator. The effectiveness of the test rests on the fact that the initial condition has permanent effects on the trajectory of a time series in the presence of a unit root. To measure the effects of the initial condition, the present paper employs cross‐sectional regressions using the first time‐series observations as a regressor and the last as a dependent variable. If there is a unit root in every individual time series, the coefficient of the regressor is equal to one. The t‐ratios for the coefficient are this paper's test statistics and have a standard normal distribution in the limit. The t‐ratios are based on the OLS estimator and the instrumental variables estimator that uses reshuffled regressors as instruments. The test proposed in this paper makes it possible to test for a unit root even at T = 2 as long as N is large. Simulation results show that test statistics have reasonable empirical size and power. The test is applied to college graduates' monthly real wage in South Korea. The number of time‐series observations for this data is only two. The null hypothesis of a unit root is rejected against the alternative of stationarity.     

Information and efficiency in political stock markets: using computerized markets to predict election results

This study concentrates on four computerized political markets in Germany between 1990 and 1998. While this new method for the prediction of election events worked quite well in the USA it did not perform as well in Germany. Searching for the causes of this distinction it is shown that, in contrast to the findings of Forsythe et al. (1992 Forsythe, R, Nelson, F, Neumann, GR and Wright, J. 1992. Anatomy of an experimental political stock market. American Economic Review, 82: 1142–61.  ), (i) extraordinary profits were achieved less by people who took advantage of other people's anomalies than by those people who acquired an advantage from the existence of asymmetric information, (ii) the marginal trader hypothesis does not hold when applied to German markets, and that (iii) traders relied on public opinion polls. It is argued that these distinctions are caused by the differences in the German and the US voting systems. Additionally, it is shown that to a certain extent (iv) election markets were able to predict the contemporary mood of the electorate without the help of public opinion polls, (v) first of all the informed traders used public opinion polls as a source of information, and (vi) prices themselves became a source of information on which expectations were based.     

A Hausman–Taylor instrumental variable approach to the penalized estimation of quantile panel models

This paper proposes an _?1${?}_1$ penalized quantile regression estimator which adapts the Hausman–Taylor instrumental variable approach in order to address the bias resulting from the shrinkage of the individual effects.     

Moment Estimation of the Probit Model with an Endogenous Continuous Regressor

We propose a generalized method of moments (GMM) estimator with optimal instruments for a probit model that includes a continuous endogenous regressor. This GMM estimator incorporates the probit error and the heteroscedasticity of the error term in the first‐stage equation in order to construct the optimal instruments. The estimator estimates the structural equation and the first‐stage equation jointly and, based on this joint moment condition, is efficient within the class of GMM estimators. To estimate the heteroscedasticity of the error term of the first‐stage equation, we use the k‐nearest neighbour (k‐nn) non‐parametric estimation procedure. Our Monte Carlo simulation shows that in the presence of heteroscedasticity and endogeneity, our GMM estimator outperforms the two‐stage conditional maximum likelihood estimator. Our results suggest that in the presence of heteroscedasticity in the first‐stage equation, the proposed GMM estimator with optimal instruments is a useful option for researchers.     

Partial identification in binary response models with nonignorable nonresponses

This study investigates the identification of parameters in semiparametric binary response models of the form y=1(x^′β+v+ε>0)$y=1(x^{\prime }\beta +v+\epsilon >0)$ when there are nonignorable nonresponses. We propose an estimation procedure for the identified set, the set of parameters that are observationally indistinguishable from the true value β$\beta$, based on the special regressor approach of Lewbel (2000). We show that the estimator for the identified set is consistent in the Hausdorff metric.     

EFFICIENT LEARNING AND JOB TURNOVER IN THE LABOR MARKET

This article nests a continuous‐time learning model la Jovanovic (Journal of Political Economy 92 (1984), 108–22) into a directed on‐the‐job search framework. We prove that the socially efficient allocation is separable, that is, the workers' value functions and optimal controls are independent of both the distribution of workers across their current match qualities and the unemployment rate. We characterize the dynamics of job transitions in the efficient allocation. Furthermore, when the matching technology is linear, our numerical results show that increasing the vacancy creation cost and the speed of learning have ambiguous effects on the unemployment rate and aggregate job transition.     

DIRECTED SEARCH,COORDINATION FAILURE,AND SELLER PROFITS: AN EXPERIMENTAL COMPARISON OF POSTED PRICING WITH SINGLE AND MULTIPLE PRICES

We experimentally examine posted pricing and directed search. In one treatment, capacity‐constrained sellers post fixed prices, which buyers observe before choosing whom to visit. In the other, firms post both “single‐buyer” (applied when one buyer visits) and “multibuyer” (when multiple buyers visit) prices. We find, based on a 2 × 2 (two buyers and two sellers) market and a follow‐up experiment with 3 and 2 × 3 markets, that multibuyer prices can be lower than single‐buyer prices or prices in the one‐price treatment. Also, allowing the multibuyer price does not affect seller profits and increases market frictions.     

Reciprocity in evolving social networks

We study the viability of conditional cooperation in a dynamically evolving social network. The network possesses the small world property, with high clustering coefficient but low characteristic path length. The interaction among linked individuals takes the form of a multiperson prisoners’ dilemma, and actions can be conditioned on the past behavior of one’s neighbors. Individuals adjust their strategies based on performance within their neighborhood, and both strategies and the network itself are subject to random perturbation. We find that the long-run frequency of cooperation is higher under the following conditions: (i) the interaction radius is neither too small nor too large, (ii) clustering is high and characteristic path length low, (iii) the mutation rate of strategies is small, and (iv) the rate of adjustment in strategies is neither too fast nor too slow.

Unionization,international integration,and selection

Abstract We study how unionization affects competitive selection between heterogeneous firms when wage negotiations can occur at the firm or at the profit‐centre level. With productivity specific wages, an increase in union power has: (i) a selection‐softening; (ii) a counter‐competitive; (iii) a wage‐inequality; and (iv) a variety effect. In a two‐country asymmetric setting, stronger unions soften competition for domestic firms and toughen it for exporters. With profit‐centre bargaining, we show how trade liberalization can affect wage inequality among identical workers both across firms (via its effects on competitive selection) and within firms (via wage discrimination across destination markets).     

Convergence and approximation results for non-cooperative Bayesian games: Learning theorems

Summary LetT denote a continuous time horizon and {G ^t :tT} be a net (generalized sequence) of Bayesian games. We show that: (i) if {x ^t : tT} is a net of Bayesian Nash Equilibrium (BNE) strategies for G^t we can extract a subsequence which converges to a limit full information BNE strategy for a one shot limit full information Bayesian game, (ii) If {x ^t : tT} is a net of approximate or _t-BNE strategies for the game G^t we can still extract a subsequence which converges to the one shot limit full information equilibrium BNE strategy, (iii) Given a limit full information BNE strategy of a one shot limit full information Bayesian game, we can find a net of _t-BNE strategies {x ^t : tT} in {G ^t :tT} which converges to the limit full information BNE strategy of the one shot game.We wish to thank Larry Blume, Mark Feldman, Jim Jordan, Charlie Kahn, Stefan Krasa, Gregory Michalopoulos, Wayne Shafer, Bart Taub, and Anne Villamil for several useful discussions. The financial support of the University of Illinois at Urbana-Champaign Campus Research Board is gratefully acknowledged.     

Institutions and growth: evidence from estimation methods robust to weak instruments

This article focuses on the empirical approach proposed by Hall and Jones (1999 Hall, RE and Jones, CI(HJ99). 1999. Why do some countries produce so much more output per worker than others?. The Quarterly Journal of Economics, 114: 83–116. [Crossref], [Web of Science ®] , [Google Scholar]) to estimate the effect of what they call ‘social infrastructure’ on productivity across countries. We consider the issue of weak identification in their linear instrumental variables model. The evidence obtained from partially robust estimators, such as the k-class and jackknife estimators, is interpreted on the basis of Monte Carlo studies. Our findings suggest that using certain k-class estimators allows exclusive reliance on the linguistic variables to instrument for institutional quality despite their low correlation with the endogenous regressor in question.     

Exact equivalence of instrumental variable estimators in an error component structural system

The paper establishes an equivalence result in the context of anm-equation error component structural system, whose disturbances have the usual three-component structure, and whose equations feature explanatory variables of the formz _i, z_t andz _it; the latter vary (respectively) only over individuals, only over time, and over both. Under the stochastic specification assumed, it is shown that the alternative instrumental variables (IV) estimators commonly used in the special cases of this system are all equivalent (numerically identical); the result is a generalization of the equivalences established previously for the special cases. In the single equation (m=1) context, the equivalence requires that the IV set contain variables of the formz _i and/orz _t, and further, in numbers determined by the ranks of (respectively) the individuals-mean and time-mean matrices of the instruments. If such an IV set is common to all equations, the equivalence also holds for the system under joint estimation. The result is used to recommend a couple of estimators for use in panel data, on grounds of computational simplicity.This is a revision of the December 1990 draft with the same title, and is a substantial revision of the April 1990 version entitled: Analysis of an error component structural system. This revision has benefited from comments received from a referee and a editor of this journal. I came to know from an anonymous reader that the equivalence criterion developed in my 1990 a article, used here and the two earlier versions, was infact obtained previously in an unpublished paper by Balestra (1988). Balestra's paper, which was made available to me by Badi Baltagi at the time of this revision, and subsequently by Balestra, considers the equivalence of ^b, ^c and one other estimator which differs from our ^a. Errors, if any, are my responsibility.     

Farsightedly stable networks

A set of networks G is pairwise farsightedly stable (i) if all possible farsighted pairwise deviations from any network g G to a network outside G are deterred by the threat of ending worse off or equally well off, (ii) if there exists a farsighted improving path from any network outside the set leading to some network in the set, and (iii) if there is no proper subset of G satisfying conditions (i) and (ii). A non-empty pairwise farsightedly stable set always exists. We provide a full characterization of unique pairwise farsightedly stable sets of networks. Contrary to other pairwise concepts, pairwise farsighted stability yields a Pareto dominant network, if it exists, as the unique outcome. Finally, we study the relationship between pairwise farsighted stability and other concepts such as the largest pairwise consistent set and the von Neumann–Morgenstern pairwise farsightedly stable set.     

When sunspots don't matter

Summary We show that a finite, competitive economy isimmune to sunspots if (i) preferences are strictly convex, (ii) the set of feasible allocations is convex, and (iii) the contingent-claims market is perfect. The conditions (i)–(ii) cover some, but not all, economies with nonconvex technologies. Based on an indivisible-good example, we show that even economies with strictly convex preferences and full insurance arenot in general immune from sunspots. We also show that (1) the sufficient conditions (i)–(iii) are not necessary for sunspot immunity and (2)ex-ante efficiency is not necessary for immunity from sunspots.This paper is based on an earlier paper, Indivisibilities in Production, and Sunspot Equilibrium, presented at the 1990 S.E.D.C. Meetings, Minneapolis-St. Paul, June 1990. The research support of NSF Grant SES-9012780, the Center for Analytic Economics, and the Thorne Fund is gratefully acknowledged.     

PAIRWISE DIFFERENCE ESTIMATION WITH NONPARAMETRIC CONTROL VARIABLES*

This article extends the pairwise difference estimators for various semilinear limited dependent variable models proposed by Honoré and Powell (Identification and Inference in Econometric Models. Essays in Honor of Thomas Rothenberg Cambridge: Cambridge University Press, 2005) to permit the regressor appearing in the nonparametric component to itself depend upon a conditional expectation that is nonparametrically estimated. This permits the estimation approach to be applied to nonlinear models with sample selectivity and/or endogeneity, in which a “control variable” for selectivity or endogeneity is nonparametrically estimated. We develop the relevant asymptotic theory for the proposed estimators and we illustrate the theory to derive the asymptotic distribution of the estimator for the partially linear logit model.     

Marginal Subsidies in Tullock Contests

In a general Tullock contest, we examine a situation where a limited resource can be used to provide marginal subsidies to either player (weak or strong), or to increase the prize directly. We show that to maximize total effort, subsidizing the weak/strong player is preferred when the contest is sufficiently accurate/inaccurate. This result generalizes to n‐player lottery contests. In a lottery contest (Tullock contest with ), we derive the optimal scheme for a full range of resource: when the resource is small, it is optimal to only subsidize the weak player; when it is large, both players should be subsidized simultaneously.     

FISCAL POLICY AND ASSET PRICES

We analyse the impact of fiscal policy on asset prices using a panel vector auto‐regressive (PVAR) approach and quarterly data for ten industrialized countries. We find that positive fiscal shocks lead to a temporary fall in stock prices and a gradual and persistent decrease in housing prices. The empirical findings also point to: (i) a contractionary effect of fiscal policy on output in line with the existence of crowding‐out effects and the deterioration of credit conditions; (ii) a weakening of the effectiveness of fiscal policy in recent times; (iii) a more persistent response of asset prices for countries with a lower degree of openness; (iv) a larger impact of fiscal policy on asset prices for small countries; (v) a close link between the responsiveness of asset prices to fiscal policy and the government’s size; (vi) an increase of the sensitivity of asset prices to fiscal policy shocks following the process of financial deregulation and mortgage liberalization; and (vii) significant fiscal multiplier effects in the context of severe housing busts. Finally, the evidence suggests that changes in equity prices may help governments towards consolidation of public finances.     

POLLUTION PERMIT SYSTEMS AND FIRM DYNAMICS: HOW DOES THE ALLOCATION SCHEME MATTER?*

I use a firm dynamics model to compare two permit allocation schemes commonly used in pollution permit systems. In the first, closing plants keep their permits, and new entrants do not get them, whereas in the second, closing plants lose their permits, and new entrants get free allowances. Calibrating the model with data from power plants participating in the U.S. program, I find that, compared to the first scheme, in the second arrangement, (i) plants stay, on average, 3.6 years longer and (ii) although the aggregate emission rate is lower, the plant distribution displays more dirty and low‐productivity plants.     

Bank–firms topology in Italy

An empirical analysis of the Italian system of banks and firms is carried out using the network theory. The emerging architecture of this economic network shows peculiar behaviors: (i) Multiple lending is very widespread; (ii) Small firms are preferentially financed by small banks; (iii) Large firms are financed by many banks; (iv) the ratio between loans and deposits is much higher for large banks than for small banks, while (v) strong size heterogeneity appears among co-financing banks, and (vi) the spanning-tree is very hierarchical.