Do Spillovers Stimulate Incremental or Drastic Product Innovations? Evidence from German Establishment Data*

Despite the generally recognized importance of knowledge spillovers, the empirical literature is essentially silent on the type of innovation stimulated by spillovers. We estimate the determinants of product innovations differing in their degree of newness to the adopting firm. Knowledge spillovers from rivals have a positive impact on incremental innovations. This impact is largely independent of participation in R&D cooperation. Spillovers exert no such independent influence on drastic innovation activities. The results support the hypothesis that establishments face difficulties in using knowledge that comes from areas they are not familiar with. Establishments exploit spillovers for incremental innovations rather than for drastic innovations. To some degree R&D cooperation can help to overcome the difficulties in using spillovers for drastic innovations. Furthermore, our estimates provide evidence that the firm's own R&D effort and the use of outside information are substitutes.     

No Mangoes in the Tundra: Spatial Heterogeneity in Agricultural Productivity Analysis*

In line with the wider macro productivity literature existing studies of agricultural production largely neglect technology heterogeneity, variable time‐series properties and the potential for heterogeneous but correlated total factor productivity (TFP) across countries. Our empirical approach accommodates these difficulties and seeks to model the nature of the cross‐section dependence in a sample of 128 countries (1961–2002). Our results suggest that agro‐climatic environment drives similarity in TFP evolution across countries with heterogeneous production technology. This provides a possible explanation for the failure of technology transfer from advanced countries of the temperate ‘North’ to arid and/or equatorial developing countries of the ‘South’.     

The Dynamics of Returns to Education in Kenyan and Tanzanian Manufacturing*

We use micro data on manufacturing employees in Kenya and Tanzania to estimate returns to education and investigate the shape of the earnings function in the period 1993–2001. In Kenya, there have been long‐run falls in the returns to education while for Tanzania there is evidence of rising returns in the 1990s. The earnings functions are convex for both countries and this result is robust to endogeneity. Convexity may be part of the explanation as to how rapid expansion of education in Africa has generated so little growth if expansion has been concentrated at lower levels of education.     

Trade,Technology and the Labour Market: The Case of South Africa*

This study advances previous work on the effects of trade and technological change on labour markets within the framework of Heckscher–Ohlin trade theory. We provide evidence for an unskilled labour abundant developing country by employing dynamic heterogeneous panel estimation techniques. For South African manufacturing, trade‐mandated increases in earnings are positive for labour and negative for capital whilst technology‐mandated increases are negative for both factors. We also find it important to take account of endogeneity issues in analysing the impact of technology and price changes on factor returns and in isolating factor‐ and sector‐bias of technological changes.     

The Impact of Training on Productivity and Wages: Evidence from British Panel Data*

It is standard in the literature on training to use wages as a sufficient statistic for productivity. This paper examines the effects of work‐related training on direct measures of productivity. Using a new panel of British industries 1983–96 and a variety of estimation techniques we find that work‐related training is associated with significantly higher productivity. A 1% point increase in training is associated with an increase in value added per hour of about 0.6% and an increase in hourly wages of about 0.3%. We also show evidence using individual‐level data sets that is suggestive of training externalities.     

Price Stickiness in the US and Europe Revisited: Evidence from Internet Prices*

This paper compares price stickiness on the Internet and in traditional brick‐and‐mortar stores and examines differences across five countries: France, Germany, Italy, the UK and the US. Contrary to conventional retail prices, we find that Internet prices change less often in the US than in EU countries. However, this does not hold for all product categories. Second, prices on the Internet are not necessarily more flexible than prices in brick‐and‐mortar stores. Third, our dataset reveals substantial heterogeneity in the frequency of price changes across Internet shops. Finally, panel logit estimates suggest that the likelihood of observing a price change is a function of both state‐dependent and time‐dependent factors.     

ICT Adoption and Heterogeneity in Production Technologies: Evidence for Chilean Retailers*

The adoption of information and communication technology (ICT) can have far‐reaching effects on the nature of production technologies. Because ICT adoption is incomplete, especially in developing countries, different groups of firms will have different production technologies. We estimate a latent class stochastic frontier model, which allows us to test for the existence of multiple production technologies across firms and consider the associated implications for efficiency measures. We use a unique data set of Chilean retailers, which includes detailed information on ICT adoption. We find three distinct production technologies. The probability of membership in a more productive group is positively related to ICT use.     

Weak Identification of Forward‐looking Models in Monetary Economics*

Recently, single‐equation estimation by the generalized method of moments (GMM) has become popular in the monetary economics literature, for estimating forward‐looking models with rational expectations. We discuss a method for analysing the empirical identification of such models that exploits their dynamic structure and the assumption of rational expectations. This allows us to judge the reliability of the resulting GMM estimation and inference and reveals the potential sources of weak identification. With reference to the New Keynesian Phillips curve of Galí and Gertler [Journal of Monetary Economics (1999) Vol. 44, 195] and the forward‐looking Taylor rules of Clarida, Galí and Gertler [Quarterly Journal of Economics (2000) Vol. 115, 147], we demonstrate that the usual ‘weak instruments’ problem can arise naturally, when the predictable variation in inflation is small relative to unpredictable future shocks (news). Hence, we conclude that those models are less reliably estimated over periods when inflation has been under effective policy control.     

Efficiency and Seasonality in the UK Housing Market, 1991–2001*

This paper considers the informational efficiency of the UK owner‐occupied housing market over the period 1991–2001. Original small‐area, monthly, quality‐adjusted house price index series are developed from raw housing transaction observations for a number of UK counties and cities. These series are then tested in an autoregressive setting for characteristics indicative of weak market efficiency and seasonality. The major conclusion drawn is that there exists little evidence to support notions of inefficiency in these markets over the period considered.     

Testing for Heteroskedasticity and Predictive Failure in Linear Regression Models*

It is argued that, when researchers wish to carry out a Chow test of the significance of prediction errors, it is necessary to assume homoskedasticity because standard results on heteroskedasticity‐robust tests are not available. The effects of heteroskedasticity on the Chow prediction error test are examined. The implementation of tests for heteroskedasticity is discussed, with the case in which the regressors include dummy variables for prediction error tests receiving special attention. Monte Carlo results are reported.     

A Note on the Theme of Too Many Instruments*

The difference and system generalized method of moments (GMM) estimators are growing in popularity. As implemented in popular software, the estimators easily generate instruments that are numerous and, in system GMM, potentially suspect. A large instrument collection overfits endogenous variables even as it weakens the Hansen test of the instruments’ joint validity. This paper reviews the evidence on the effects of instrument proliferation, and describes and simulates simple ways to control it. It illustrates the dangers by replicating Forbes [American Economic Review (2000) Vol. 90, pp. 869–887] on income inequality and Levine et al. [Journal of Monetary Economics] (2000) Vol. 46, pp. 31–77] on financial sector development. Results in both papers appear driven by previously undetected endogeneity.     

Occupational Labour Demand and the Sources of Non‐neutral Technical Change*

This article introduces a two‐step empirical approach for examining both the nature and sources of non‐neutral technical change across multiple occupations. First, conventional labour‐demand parameter estimates and unbiased tests for neutrality are obtained in the context of a flexible cost system. The resulting input‐specific indices of technical change, unconstrained with respect to time path, facilitate subsequent evaluation of proposed sources. In our application to employment decisions of airline firms, we find labour‐saving technical change that is non‐neutral across occupations. We also document occupation‐specific responses to aircraft technology adoption, route system developments and an unprecedented range of technical change elements.

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Bradford Smith: An Econometrician Decades Ahead of His Time*

This article attempts to rehabilitate Bradford Smith, who in 1926 published a short article in the Journal of the American Statistical Association in which he considered the implications of detrending time series by either deviations‐from‐trend or first‐differencing prior to regression. His discussion covers such topics as the permanent‐transitory innovation distinction inherent in difference and trend stationary processes, common factor restrictions and general‐to‐specific modelling. These have all become mainstays of modern time‐series econometrics, yet there does not appear to be even one reference to Smith's paper in all the years since its publication.     

The size distribution of innovations revisited: An application of extreme value statistics to citation and value measures of patent significance

This paper focuses on the analysis of size distributions of innovations, which are known to be highly skewed. We use patent citations as one indicator of innovation significance, constructing two large datasets from the European and US Patent Offices at a high level of aggregation, and the Trajtenberg [1990, A penny for your quotes: patent citations and the value of innovations. Rand Journal of Economics 21(1), 172–187] dataset on CT scanners at a very low one. We also study self-assessed reports of patented innovation values using two very recent patent valuation datasets from the Netherlands and the UK, as well as a small dataset of patent licence revenues of Harvard University. Statistical methods are applied to analyse the properties of the empirical size distributions, where we put special emphasis on testing for the existence of ‘heavy tails’, i.e., whether or not the probability of very large innovations declines more slowly than exponentially. While overall the distributions appear to resemble a lognormal, we argue that the tails are indeed fat. We invoke some recent results from extreme value statistics and apply the Hill [1975. A simple general approach to inference about the tails of a distribution. The Annals of Statistics 3, 1163–1174] estimator with data-driven cut-offs to determine the tail index for the right tails of all datasets except the NL and UK patent valuations. On these latter datasets we use a maximum likelihood estimator for grouped data to estimate the tail index for varying definitions of the right tail. We find significantly and consistently lower tail estimates for the returns data than the citation data (around 0.6–1 vs. 3–5). The EPO and US patent citation tail indices are roughly constant over time, but the latter estimates are significantly lower than the former. The heaviness of the tails, particularly as measured by value indicators, we argue, has significant implications for technology policy and growth theory, since the second and possibly even the first moments of these distributions may not exist.     

Testing the New Keynesian Phillips Curve Through Vector Autoregressive Models: Results from the Euro Area*

This paper addresses the issue of testing the ‘hybrid’ New Keynesian Phillips curve (NKPC) through vector autoregressive (VAR) systems and likelihood methods, giving special emphasis to the case where the variables are non‐stationary. The idea is to use a VAR for both the inflation rate and the explanatory variable(s) to approximate the dynamics of the system and derive testable restrictions. Attention is focused on the ‘inexact’ formulation of the NKPC. Empirical results over the period 1971–98 show that the NKPC is far from providing a ‘good first approximation’ of inflation dynamics in the Euro area.     

Technical Efficiency in a Semi-Formal Financial Sector: The Case of Mexico*

The semi-formal financial sector in Mexico is playing an increasingly important role in serving a largely poor, rural clientele. A stochastic frontier with non-monotonic marginal effects [ Wang, Journal of Productivity Analysis (2002 ), Vol. 18, pp. 241–253] reveals a wide disparity in technical efficiency levels among 190 Mexican semi-formal financial intermediaries. The results show that technology, average loan size, rural outreach and institutional age are all positively associated with technical efficiency. The marginal effects vary widely and, in some cases, the effects are non-monotonic over percentile groups. The results indicate that strengthening younger, technologically undeveloped financial institutions will have the strongest marginal benefit in revitalizing the rural financial sector.     

Testing the Political Replacement Effect: A Panel Data Analysis*

This article tests for the existence of the political replacement effect, as suggested by Acemoglu and Robinson: [American Political Science Review, Vol. 100, pp. 115–131]. They argue that the implementation of market‐oriented reform is crucially driven by the political calculus of incumbent governments: they implement economic policy change if such a choice is not expected to reduce their chances to retain power. This implies a non‐monotonic relationship between the level of political competition and the extent of economic reform. We test this hypothesis using data for 102 countries over the period 1980 to 2005. Our results strongly support the theory.     

Influences of the Business Environment on Manufacturing Firms Technical Efficiencies: The Côte d’Ivoire Case

An unbalanced panel is used to estimate technical and managerial efficiency levels of manufacturing firms in Côte d’Ivoire. A stochastic frontier production model with non-neutral effects on technical efficiency of the business environment variables is specified. This specification allows to evaluate and to compare technical efficiencies and efficiency levels net of business environment influences. In order to determine net efficiency levels in the non-neutral case, a practical method based on the definition of an artificial environment is proposed. Results suggest that informal firms are less technically efficient than formal firms whereas their managerial performances are closed to those of formal firms.     

On the Applicability of the Sieve Bootstrap in Time Series Panels*

In this article, we investigate the validity of the univariate autoregressive sieve bootstrap applied to time series panels characterized by general forms of cross‐sectional dependence, including but not restricted to cointegration. Using the final equations approach we show that while it is possible to write such a panel as a collection of infinite order autoregressive equations, the innovations of these equations are not vector white noise. This causes the univariate autoregressive sieve bootstrap to be invalid in such panels. We illustrate this result with a small numerical example using a simple DGP for which the sieve bootstrap is invalid, and show that the extent of the invalidity depends on the value of specific parameters. We also show that Monte Carlo simulations in small samples can be misleading about the validity of the univariate autoregressive sieve bootstrap. The results in this article serve as a warning about the practical use of the autoregressive sieve bootstrap in panels where cross‐sectional dependence of general form may be present.     

On Lumpiness in the Replacement and Expansion of Capital*

We estimate a model of homogeneous capital investment with two installation possibilities – replacement and expansion using observations at the establishment level. We find that regime switches identified by ad hoc measures of lumpy investment do not adequately distinguish expansionary from replacement activities. In fact, during periods of expansion, firms spend just as much on replacement capital. Also, using the common 20% rule would not assign a spike to almost 65% of all observations that include expansionary investment in this dataset. Finally, replacement although less responsive to fundamentals than expansions cannot be regarded as an autonomous part of investment.