Estimation of the Gravity Equation of Bilateral Trade in the Presence of Zero Flows

The gravity model is the workhorse model to describe and explain variation in bilateral trade empirically. Consistent with both Heckscher-Ohlin models and models of imperfect competition and trade, this versatile model has proven to be very successful, explaining a large part of the variance in trade flows. However, the loglinear model cannot straightforwardly account for the occurrence of zero-valued trade flows between pairs of countries. This paper investigates the various approaches suggested to deal with zero flows. Apart from the option to omit the zero flows from the sample, various extensions of Tobit estimation, truncated regression, probit regression and substitutions for zero flows have been suggested. We argue that the choice of method should be based on both economic and econometric considerations. The sample selection model appears to fit both considerations best. Moreover, we show that the choice of method may matter greatly for the results, especially if the fraction of zero flows in the sample is large. In the end, the results surprisingly suggest that the simplest solution, to omit zero flows from the sample, often leads to acceptable results, although the sample selection model is preferred theoretically and econometrically.

Linking Trade and Transport Statistics: the Dutch Case

International trade flows are important for a trading nation such as the Netherlands. They are an important source of income, value added, and welfare. Trade flows are strongly related to transport flows of goods to and from a country. However, not all international transport flows through a country are registered as merchandize trade flows. For example, transit flows of goods are not recorded in international merchandize trade statistics. Such flows can just as well serve as a basis for value added, though. For example, goods transferred in Rotterdam harbour and transported and distributed by Dutch logistics firms create a basis for value added in services trade. Moreover, transport flows of goods entail costs as well, such as the costs of traffic congestion and environmental pollution. Therefore, it is of interest to have good information on the value and quantities of goods transported through countries, and the modes of transport used for various types of flows. For this purpose, we need integrated statistics on trade flows and transport flows in goods. To be able to match trade and transit flows with transport statistics, complete and plausible information on mode of transport and gross weight is needed. This paper describes the scope and coverage of trade statistics in comparison to transport statistics for the Netherlands. We use transport statistics to allocate the plausible mode of transport to trade and transit flows. Creating an integrated view on trade and transport flows in goods, the paper intends to contribute to an improved understanding of the impact of merchandize trade and transit flows on the economy, both in terms of domestic value added and in terms of potential social costs related to congestion and the emission of pollutants.

Distance Decay in International Trade Patterns - a Meta-analysis

Trade costs remain an important barrier to international trade in today’s globalizing economy. Despite the popular discussion on the “death of distance”, distance is still an important source of trade costs and continues to have an irrevocable impact on the patterns of international trade. The literature identifies various factors that can explain the importance of geographical proximity for bilateral trade. First, transport costs and costs of timeliness increase with distance. Moreover, psychic distance increases as well. Because of cultural unfamiliarity and information costs, traders have less knowledge of distant markets. Empirical estimates of the distance effect in trade abound. The evidence indicates that distance still matters for trade. However, differences in estimated effects across the literature make generalizations about the distance effect and its development over time more difficult. This paper performs a meta-analysis of existing empirical studies of bilateral trade, in order to contribute to our understanding of distance decay in trade. Meta-analysis is a statistical analysis of a set of existing empirical results in a specific research area, in order to integrate the findings. It constitutes a quantitative survey of the literature that explicitly addresses the causes of cross-study variation in empirical outcomes. To perform the meta-analysis, a sample of gravity studies was constructed that is as representative as possible. For this purpose, a literature search has been conducted on the Internet, using the Econlit database. Using the search string “trade and/or distance, and gravity, in all fields”, a list of 214 applicable studies has been identified. From this list, 30 studies were randomly selected into the meta-analysis sample. The paper focuses on two key issues. First, it investigates cross-estimate variation in the distance effect according to differences in, e.g., time period concerned, data type used, or empirical specification and estimation method used. Then, we analyse whether the impact of distance has declined over time.

Distance Decay in International Trade Patterns - a Meta-analysis

Trade costs remain an important barrier to international trade in today's globalizing economy. Despite the popular discussion on the "death of distance”, distance is still an important source of trade costs and continues to have an irrevocable impact on the patterns of international trade. The literature identifies various factors that can explain the importance of geographical proximity for bilateral trade. First, transport costs and costs of timeliness increase with distance. Moreover, psychic distance increases as well. Because of cultural unfamiliarity and information costs, traders have less knowledge of distant markets. Empirical estimates of the distance effect in trade abound. The evidence indicates that distance still matters for trade. However, differences in estimated effects across the literature make generalizations about the distance effect and its development over time more difficult. This paper performs a meta-analysis of existing empirical studies of bilateral trade, in order to contribute to our understanding of distance decay in trade. Meta-analysis is a statistical analysis of a set of existing empirical results in a specific research area, in order to integrate the findings. It constitutes a quantitative survey of the literature that explicitly addresses the causes of cross-study variation in empirical outcomes. To perform the meta-analysis, a sample of gravity studies was constructed that is as representative as possible. For this purpose, a literature search has been conducted on the Internet, using the Econlit database. Using the search string "trade and/or distance, and gravity, in all fields”, a list of 214 applicable studies has been identified. From this list, 30 studies were randomly selected into the meta-analysis sample. The paper focuses on two key issues. First, it investigates cross-estimate variation in the distance effect according to differences in, e.g., time period concerned, data type used, or empirical specification and estimation method used. Then, we analyse whether the impact of distance has declined over time

Determinants of regional productivity growth in Europe: an empirical analysis

Discussion on the possibilities for and barriers to income convergence and catch-up growth is at the heart of the debate on European regional economic policy. This study presents an empirical analysis of the determinants of regional productivity growth in Europe, using the most recent Cambridge Econometrics regional database, EU KLEMS growth and productivity accounts and EuroStat R&D data. We apply a reduced-form empirical specification for semi-endogenous productivity growth that allows for differences in steady state income levels and long-run growth rates. Productivity growth in a region depends on its level of human capital, the investments in R&D, and the productivity gap with the technology frontier. Empirical findings show that these factors are interrelated. Apart from a technology gap, absorptive capacity is important to realize catch-up. Both convergence and divergence of productivity across regions are possible. Results show that all considered factors have significant effect on disparity in regional productivity growth, although effects across manufacturing and service sectors are different. The estimated model also features stable dynamic properties in response to an exogenous shock. Keywords: Semi-endogenous Growth, Regional Convergence, International Transfer of Technology, human capital, R&D.

Estimation of the Gravity Equation of Bilateral Trade in the Presence of Zero Flows

The gravity model is the workhorse model to describe and explain variation in bilateral trade empirically. Consistent with both Heckscher-Ohlin models and models of imperfect competition and trade, this versatile model has proven to be very successful, explaining a large part of the variance in trade flows. However, the loglinear model cannot straightforwardly account for the occurrence of zero-valued trade flows between pairs of countries. This paper investigates the various approaches suggested to deal with zero flows. Apart from the option to omit the zero flows from the sample, various extensions of Tobit estimation, truncated regression, probit regression and substitutions for zero flows have been suggested. We argue that the choice of method should be based on both economic and econometric considerations. The sample selection model appears to fit both considerations best. Moreover, we show that the choice of method may matter greatly for the results, especially if the fraction of zero flows in the sample is large. In the end, the results surprisingly suggest that the simplest solution, to omit zero flows from the sample, often leads to acceptable results, although the sample selection model is preferred theoretically and econometrically

FIX - The fear index. Measuring market fear.

In this paper, we propose a new fear index based on (equity) option surfaces of an index and its components. The quanti¯cation of the fear level will be solely based on option price data. The index takes into account market risk via the VIX volatility barometer, liquidity risk via the concept of implied liquidity, and systemic risk and herd-behavior via the concept of comonotonicity. It thus allows us to measure an overall level of fear (excluding credit risk) in the market as well as to identify precisely the individual importance of the distinct risk components (market, liquidity or systemic risk). As a side result we also derive an upperbound for the VIX.

Ordered Preference Elicitation Strategies for Supporting Multi-Objective Decision Making

In multi-objective decision planning and learning, much attention is paid to producing optimal solution sets that contain an optimal policy for every possible user preference profile. We argue that the step that follows, i.e, determining which policy to execute by maximising the user's intrinsic utility function over this (possibly infinite) set, is under-studied. This paper aims to fill this gap. We build on previous work on Gaussian processes and pairwise comparisons for preference modelling, extend it to the multi-objective decision support scenario, and propose new ordered preference elicitation strategies based on ranking and clustering. Our main contribution is an in-depth evaluation of these strategies using computer and human-based experiments. We show that our proposed elicitation strategies outperform the currently used pairwise methods, and found that users prefer ranking most. Our experiments further show that utilising monotonicity information in GPs by using a linear prior mean at the start and virtual comparisons to the nadir and ideal points, increases performance. We demonstrate our decision support framework in a real-world study on traffic regulation, conducted with the city of Amsterdam.Comment: AAMAS 2018, Source code at https://github.com/lmzintgraf/gp_pref_elici