Is there a slowdown in agricultural productivity growth in South America?

This article estimates agricultural productivity growth in 10 South American countries in 1969–2009 with the objective of investigating if the slowdown being measured in other countries is present in the region. Results show that productivity growth accounts for half of the three‐fold increase in agricultural output during this period and that performance is sensitive to R&D investments in the sector. The slowdown found for the 1990s to 2000s in the U.S. and some European economies does not seem to be present yet in South America. The region's total factor productivity (TFP) growth rate increased steadily from 1.07% during the 1970s to 2.29% during the 2000s. Given lags in adoption and the adaptive nature of innovations in these economies, we have yet to see the potential effects in South American agriculture of decreases in R&D in advanced economies.     

Spatial determinants of productivity growth on agri‐food Spanish firms: a comparison between cooperatives and investor‐owned firms

This study analyses the effect of the spatial factor, location, and interaction effects among peer companies, on the productivity growth of agri‐food companies in Spain. With this aim, we build a productivity growth index and apply a multiequational Seemingly Unrelated Regression on a sample of 344 Spanish cooperatives and investor‐owned firms for the period 2010–2012. Our findings show that agri‐food firms are influenced by spatial factors finding interesting differences between cooperatives and investor‐owned firms. With regard to the geographical location, cooperatives in the western of Spain show higher productivity growth rates, whereas investor‐owned firms in the northeast of Spain present better results. The interaction effect among closer peer companies is also a relevant factor to determine the productivity growth in agri‐food companies. This factor is more relevant for cooperatives than for investor‐owned firms.     

Evolving splines and seasonal unit roots in weekly agricultural prices

The univariate statistical properties of agricultural price series need to be examined as a first step in the analysis of price transmission mechanisms. However, in the case of weekly price series, increasingly available, the testing procedures usually applied in this step are not suitable to deal with evolving seasonal effects. In this study, a method of testing for seasonal unit roots in weekly series of agricultural prices is described. When the deterministic seasonal component does not remain constant over time, the restricted evolving spline model (RESM) is shown to be a useful parametric formulation to capture the deterministic seasonal pattern. Therefore, the RESM model should be included as a deterministic component in auxiliary regression for unit root tests at seasonal frequencies. This proposal is applied to three weekly series of Canary Islands banana prices. From the standard seasonal unit root tests, the null hypothesis is failed to be rejected at the 5% or 10% significance level at some seasonal frequencies for each one of the series. Once critical values are obtained by simulation exercises when the RESM model is included, the hypotheses of unit root are rejected at each one of the seasonal frequencies for all of the three series.     

On the dynamics of inflation persistence around the world

We study the dynamics of inflation persistence in 45 countries for the period 1960–2008 using a recently developed test for multiple changes in persistence, which decomposes the sample information between adjacent I (0) and I (1) periods. We find that: (i) inflation persistence and average inflation tend to fall and rise at the same time; (ii) in some countries there are changes in the level of inflation which do not seem to be related to changes in inflation persistence; (iii) around half of the countries analyzed do not present any burst of I (1) behavior, and hence have stationary inflation throughout; (iv) for the other half, we detect switches of the type I (0) ? I (1) ? I (0), hence, inflation persistence, when it has occurred, has been temporal; and, (v) for about half of the countries in which inflation has presented I (1) behavior, persistent inflation lasted more than a decade. In addition, we find that in the last 50 years there have been mainly two episodes where long bursts of I (1) inflation took place simultaneously among groups of countries. In general, the “Great Inflation” occurred during the seventies and eighties in advanced economies, whereas it occurred during the eighties and nineties in emerging economies, particularly in Latin America.     

Co‐movements in commodity prices: a note based on network analysis

This article analyses co‐movements in a wide group of commodity prices during the time period 1992–2010. Our methodological approach is based on the correlation matrix and the networks inside. Through this approach we are able to summarize global interaction and interdependence, capturing the existing heterogeneity in the degrees of synchronization between commodity prices. Our results produce two main findings: (a) we do not observe a persistent increase in the degree of co‐movement of the commodity prices in our time sample, however from mid‐2008 to the end of 2009 co‐movements almost doubled when compared with the average correlation; (b) we observe three groups of commodities which have exhibited similar price dynamics (metals, oil and grains, and oilseeds) and which have increased their degree of co‐movement during the sampled period.     

How do Agricultural Programmes Alter Crop Production? Evidence from Ecuador

Evaluating agricultural programmes requires considering not only the programmes’ influence on input and output indicators, but also considering the relationship between these indicators as embodied in the production technology. This article examines the impact on production of an intervention in the Ecuadorian Sierra designed to improve returns to potato production through training and through linking smallholders to high‐value markets. Critical to identifying the impact of the programme is the careful construction of a counterfactual and meticulous data collection. To assess the impact of the programme on production, a weighted estimation, where weights are constructed through propensity score matching, is employed to estimate a production function within a damage abatement framework. The function incorporates a series of interaction terms to assess the impact of the programme on the production technology. The findings provide evidence that the programme enhances yields both through a general shift in technology as well as increased input use. The results suggest that the use of effective farming techniques that are learned through the programme induce this technological shift.     

Sector-specific capital, “Bang-bang” investment,and the Filippov solution

Bang-bang investment in a two-sector growth model with immobile capital is rational and leads to a unique and globally stable long-run equilibrium along a sliding trajectory. This steady state coincides with the stationary equilibrium in the traditional model with non-sector-specific capital.This article was written while the authors were visiting scholars at Cornell University. We gratefully acknowledge financial assistance from the Erasmus University Trust Fund and the Netherlands Scientific Organization. We would like to thank, without implicating, two anonymous referees, Martijn Herrmann, Jean-Marie Viaene, Claus Weddepohl, and the participants of seminars at the University of Maryland, the University of Montreal, and Erasmus University Rotterdam for perceptive remarks and useful comments. Jeroen Hinloopen and Rien Wagenvoort provided able graphical assistance. The views expressed in this article are those of the authors and not necessarily those of the World Bank.