Measuring the persistence in innovation in Spanish manufacturing firms: empirical evidence using discrete-time duration models

This paper measures the level of persistence in innovation using a large representative sample of Spanish manufacturing firms for the period 1990–2008. We determine survival in innovation activities using discrete-time duration models, which control for some of the existing problems in the continuous-time duration models used in previous studies (namely, unobserved heterogeneity and the proportional hazards assumption). This paper examines the relationship between the firm-specific characteristics of technological regimes and the persistence measured by innovative spells at the firm level. The results show that high technological opportunities, patents, cumulativeness of learning based on previous experience and accumulated R&D, as well as the use of generic knowledge provided by universities enhance persistence in innovative activity.     

On the role of unobserved preference heterogeneity in discrete choice models of labour supply

The aim of this paper is to analyse the impact of unobserved preference heterogeneity in empirical applications of discrete choice models of labour supply. Typically, unobserved heterogeneity is estimated either with continuous or discrete mixture models. However, in order to avoid estimation difficulties, most of the empirical analysis assumes a relatively constrained mixture, standard examples being models where only few coefficients are allowed to vary with independent normal distributions or with discrete distributions with few mass points. We compare labour supply elasticities obtained with these typical specifications of unobserved heterogeneity with those from a more general model that we are able to estimate through an EM algorithm for the nonparametric estimation of mixed models. Results show that labour supply elasticities change significantly with respect to a basic model without unobserved heterogeneity only when the joint distribution of the varying tastes is left completely unspecified.     

IDENTIFICATION AND ESTIMATION OF AUCTION MODEL WITH TWO‐DIMENSIONAL UNOBSERVED HETEROGENEITY*

This article investigates the empirical importance of allowing for multidimensional sources of unobserved heterogeneity in auction models with private information. It develops the estimation procedure to recover the distribution of private information in the presence of two sources of unobserved heterogeneity. It is shown that this estimation procedure identifies components of the model and produces uniformly consistent estimators of these components. The results of the estimation with highway procurement data indicate that allowing for two‐dimensional unobserved heterogeneity may significantly affect the results of estimation as well as policy‐relevant instruments derived from the estimated distributions of bidders’ costs.     

Using job changes to evaluate the bias of value of a statistical life estimates

This paper presents a new approach to obtaining unbiased estimates of the value of a statistical life (VSL) with labor market data. Investigating job changes, we combine the advantages of recent panel studies, allowing us to control for unobserved heterogeneity of workers, and conventional cross-sectional estimations, which are less affected by measurement error. We find a VSL of 6.1 million euros from pooled cross-sectional estimation, 1.5 million euros from the first-differences panel model and 2.0 million euros from the job-changer specification. Thus, ignoring individual heterogeneity causes overestimates of the VSL, whereas the attenuation bias in panel data models leads to underestimates of the VSL. Our results are less biased than former results and can be used to perform cost–benefit analyses of public projects aimed at reducing fatality risks, e.g., in the domains of environmental, health, or traffic policy.     

Reporting errors, ability heterogeneity, and returns to schooling in China

Abstract. This study is aimed at providing a more accurate estimate of the returns to schooling in China by controlling for unobserved ability heterogeneity and measurement errors. We identify a unique instrument to correct for the omitted ability bias. We find that the attenuation bias caused by measurement error dominates the omitted ability bias in the OLS estimation. Based on the GMM estimation, for young workers in China, the return to schooling is 15.0% overall and 16.9% for women.     

Bayesian estimation of duration models: An application of the multiperiod probit model

The multiperiod probit model is presented and Bayesian estimation using the Gibbs sampler with data augmentation is described. As an empirical illustration, the multiperiod probit model is then used to estimate a duration model using employment duration data for the Canadian province of New Brunswick. Bayesian estimation with unobserved heterogeneity is shown to be a simple extension of estimation of a duration model with no unobserved heterogeneity. More importantly, perhaps, some numerical problems encountered by other authors using Maximum Likelihood are avoided.I would like to thank M. Baker, G. Koop, A. Melino and D. Poirier for helpful comments and discussions. I would also like to thank M. Baker for providing his data.     

Unemployment duration models with non-stationary inflow and unobserved heterogeneity

This paper is concerned with econometric problems and methods involved when estimating duration models using data on uncompleted unemployment spells provided by standard labour force surveys. In particular, it considers how the model estimates are affected by the commonly applied assumption of stationary inflow rates when the true inflow rates are non-stationary and when different assumptions about unobserved heterogeneity are maintained.     

Economic integration agreements,border effects,and distance elasticities in the gravity equation

Using a novel common econometric specification, we examine the measurement of three important effects in international trade that historically have been addressed largely separately: the (partial) effects on trade of economic integration agreements, international borders, and bilateral distance. First, recent studies focusing on precise and unbiased estimates of effects of economic integration agreements (EIAs) on members׳ trade may be biased upward owing to inadequate control for time-varying exogenous unobservable country-pair-specific changes in bilateral export costs (possibly decreasing the costs of international relative to intranational trade); we find evidence of this bias using a properly specified gravity equation. Second, our novel methodology yields statistically significant estimates of the declining effect of “international borders” on world trade, now accounting for endogenous EIA formations and unobserved country-pair heterogeneity in initial levels. Third, we confirm recent evidence providing a solution to the “distance-elasticity puzzle,” but show that these estimates of the declining effect of distance on international trade are biased upward by not accounting for endogenous EIA formations and unobserved country-pair heterogeneity. We conclude our study with numerical general equilibrium comparative statics illustrating a substantive difference on trade effects of EIAs with and without allowance for the declining effects of international borders on world trade.     

The effect of inflation on growth

The paper examines the effect of inflation on growth in transition countries. It presents panel data evidence for 13 transition countries over the 1990–2003 period; it uses a fixed effects panel approach to account for possible bias from correlations among the unobserved effects and the observed country heterogeneity. The results find a strong, robust, negative effect on growth of inflation or its standard deviation, and one that appears to decline in magnitude as the inflation rate increases, as seen for OECD countries. And the results include a role for a normalized money demand in affecting growth, as well as for a convergence variable, a trade variable and a government share variable. Robustness of the baseline single‐equation model is examined by expanding this into a three‐equation simultaneous system of output growth, inflation and money demand that allows for possible simultaneity bias in the baseline model.     

Ethnic Networks and US Exports*

This paper provides new estimates of the effects of ethnic networks on US exports. In line with recent research, our dataset is a panel of exports from US states to 29 foreign countries. Our analysis departs from the literature in two ways, both of which show that previous estimates of the ethnic‐network elasticity of trade are sensitive to the restrictions imposed on the estimated models. Our first departure is to control for unobserved heterogeneity with properly specified fixed effects, which we can do because our dataset contains a time dimension absent from previous studies. Our second departure is to remove the restriction that the network effect is the same for all ethnicities. We find that ethnic‐network effects are much larger than has been estimated previously, although they are important only for a subset of countries.     

Sunk Costs,Firm Heterogeneity,Export Market Entry and Exit: Evidence from India

This paper analyses the role of sunk costs and firm heterogeneity in firm decision to enter and exit export markets. Employing rich firm-level data on Indian manufacturing firms, the study points out that sunk costs in terms of previous export experience significantly explain entry and exit decisions of firms in the export market. The first set of analysis involves estimation of dynamic discrete choice model using random effects probit correcting for initial conditions problem. We find evidence that previous export experience (sunk costs) matters for export decision. However, importance of sunk costs is found to depreciate rapidly. Further, analysis across sub-sample of firms accounting for firm heterogeneity factors like size and product level information supports the hypothesis of sunk costs. Second set of analysis involving firm survival in export markets using discrete-time hazard models shows evidence of negative duration dependence. We observe that those firms which continue to export for few years are less likely to exit from export markets.

     

UNMASKING THE POLLUTION HAVEN EFFECT*

We use theory and empirics to examine the effect of environmental regulations on trade flows. A simple model demonstrates how unobserved heterogeneity, endogeneity, and aggregation issues bias standard measurements of this relationship. A reduced‐form estimate of the model, using data on U.S. regulations and trade with Canada and Mexico for 130 manufacturing industries from 1977 to 1986, indicates that industries whose abatement costs increased most experienced the largest increases in net imports. For the average industry, the change in net imports we ascribe to regulatory costs amounting to 10% of the total increase in trade volume over the period.     

Comparing alternative methods to estimate gravity models of bilateral trade

The gravity equation has been traditionally used to predict trade flows across countries. However, several problems related with its empirical application still remain unsolved. The unobserved heterogeneity, the presence of heteroskedasticity in trade data or the existence of zero flows, which make the estimation of the logarithm unfeasible, are some of them. This paper provides a survey of the most recent literature concerning the specification and estimation methods of this equation. For a dataset covering 80% of world trade, the most widely extended estimators are compared, showing that the Heckman sample selection model performs better overall for the specification of gravity equation selected.     

Re-examining the threshold effects in the inflation–growth nexus with cross-sectionally dependent non-linear panel: Evidence from six industrialized economies

This paper analyzes the empirical relationship between inflation and output growth using a novel panel data estimation technique, Panel Smooth Transition Regression (PSTR) model, which takes account of the non-linearities in the data. By using a panel data set for 6 industrialized countries that enable us to control for unobserved heterogeneity at both country and time levels, we find that there exists a statistically significant negative relationship between inflation and growth for the inflation rates above the critical threshold level of 2.52%, which is endogenously determined. Furthermore, we also control cross-section dependency by using the CD test modified to non-linear context and remedy cross-section dependency with Seemingly Unrelated Regression Equations through Generalized Least Squares (SURE-GLS) and newly proposed Common Correlated Effects (CCE) estimation techniques. We find that these methods change the critical threshold value slightly. The estimated threshold values from these estimation methods are 3.18% and 2.42%, respectively.     

双边营商环境、契约依赖和贸易持续期*--基于中国企业微观数据的实证研究

在国际贸易中，贸易双方所在地的契约环境和贸易产品的契约特征是影响贸易关系的重要因素。文章基于异质性贸易理论框架，分别从产品行业特征的内因角度和地区契约环境的外因角度研究了契约因素如何通过影响风险来作用于贸易持续期，并使用 H S8分位数层面的中国海关统计数据库、世界银行营商环境调查数据库和中国工业企业数据库的匹配数据，从“企业－产品－目的地”视角进行了 COX 比例风险分析。研究表明：（1）地理契约特征对贸易持续期存在着显著影响，贸易双方所在地的契约环境优势对贸易持续期有着显著的促进作用；（2）地理契约特征对贸易持续期的影响因贸易产品的异质性契约特征而存在差异，良好的地区契约环境能够在更大的边际效应上降低违约风险，并能够在高契约依赖度的产品贸易中得到更好地发挥；（3）虽然我国的贸易关系数量在增加，但退出率却在逐年上升。文章从贸易持续期的角度来研究贸易平稳性，这对于我国今后如何提升对外贸易质量有着重要意义。     

Economies of scale and trade policy: The median voter model revisited

Why do some political economy models perform so poorly in predicting actual trade policy? Do scale economies provide the missing puzzle to our understanding of the anti-trade bias? By integrating economies of scale in production, this paper theoretically reinstates the median voter model as in Mayer [Mayer, W. (1984). Endogenous tariff formation. The American Economic Review, 74, 970–985] as a suitable political economy model in predicting trade policy. The modified model generates the scope for the anti-trade bias and predicts that sometimes economic, rather than political, considerations may lead to restrictive trade.     

The Armington assumption and the size of optimal tariffs

There has been commentary on the seeming success of the world trading system in responding to the large shock of the 2008 financial crisis without an outbreak of retaliatory market closing. The threat of large retaliatory tariffs and fears of a 1930s style downturn in trade have been associated with numerical trade modelling, which projects post retaliation optimal tariffs in excesses of 100%. In the relevant numerical modelling, it is common to use the Armington assumption of product heterogeneity by country. Here, we argue and show by numerical calculation that the widespread use of this assumption gives a large upward bias to optimal tariffs, both first step and post retaliation, relative to alternative homogenous good models used in trade theory. The reason is that optimal tariffs equal the inverse of the foreign export supply elasticity and are negatively related to the elasticity of the foreign offer curve. The Armington assumption model has a much more bowed foreign offer curve, which generates unrealistic larger optimal tariffs.     

A simple method for estimating unconditional heterogeneity distributions in correlated random effects models

I propose a general, simple approach to recovering an unconditional heterogeneity distribution when a conditional distribution has been estimated. The approach can be applied to cross section models and panel data models-both static and dynamic-with unobserved heterogeneity.     

State dependence,serial correlation and heterogeneity in the union membership dynamics

In order to distinguish the true and spurious state dependence from the complicated dynamics of union membership, the simulation estimators incorporating the lagged dependent variables, unobserved individual heterogeneity and correlations among the errors are implemented in this article to study union membership dynamics. It is found that the true state dependence of union membership under multivariate t assumption is much higher than the standard dynamic panel probit estimators which are under multivariate normal assumptions. On the other hand, the spurious state dependence (the variance of the unobserved individual heterogeneity) is estimated to be higher when using the standard dynamic panel probit estimators than under multivariate t assumption. Moreover, blacks and married men are found to have higher union membership true state dependence than whites and unmarried men.     

APPLICATION OF PANEL DATA MODELS IN BENCHMARKING ANALYSIS OF THE ELECTRICITY DISTRIBUTION SECTOR*

ABSTRACT ** : This paper explores the application of several panel data models in measuring productive efficiency of the electricity distribution sector. Stochastic Frontier Analysis has been used to estimate the cost‐efficiency of 59 distribution utilities operating over a nine‐year period in Switzerland. The estimated coefficients and inefficiency scores are compared across three different panel data models. The results indicate that individual efficiency estimates are sensitive to the econometric specification of unobserved firm‐specific heterogeneity. This paper shows that alternative panel models such as the ‘true’ random effects model proposed by Greene (2005) could be used to explore the possible impacts of unobserved firm‐specific factors on efficiency estimates. When these factors are specified as a separate stochastic term, the efficiency estimates are substantially higher suggesting that conventional models could confound efficiency differences with other unobserved variations among companies. On the other hand, refined specification of unobserved heterogeneity might lead to an underestimation of inefficiencies by mistaking potential persistent inefficiencies as external factors. Given that specification of inefficiency and heterogeneity relies on non‐testable assumptions, there is no conclusive evidence in favour of one or the other specification. However, this paper argues that alternative panel data models along with conventional estimators can be used to obtain approximate lower and upper bounds for companies' efficiency scores.