Methodological innovations in estimating the (inverse) relationship between farm productivity and farm size in a developing economy: a case study of Burundi

We use a nonparametric estimation of the production function to investigate the relationship between farm productivity and farming scale in poor smallholder agricultural systems in the north of Burundi. Burundi is one of the poorest countries in the world, with a predominant small scale subsistence farming sector. A Kernel regression is used on data of mixed cropping systems to study the determinants of production including different factors that have been identified in literature as missing variables in the testing of the inverse relationship such as soil quality, location and household heterogeneity. Household data on farm activities and crop production was gathered among 640 households in 2007 in two Northern provinces of Burundi. Four production models were specified each with different control variables. For the relatively small farms, we find clear evidence of an inverse relationship. The relatively large farms show a different pattern. Returns to scale are found to be farm scale dependent. Parametric Cobb-Douglass models tend to over-simplify the debate on returns to scale because of not accounting for the different effects of large farms. Other factors that significantly positively affect production include the soil quality and production orientation towards banana or cash crop production. Production seems to be negatively affected by field fragmentation.inverse relationship, farm size, nonparametric, Burundi, Agricultural and Food Policy, Community/Rural/Urban Development, Environmental Economics and Policy, D24, O13, Q12, Q18,

The Effect of Inventory on Purchase Incidence: Empirical Analysis of Opposing Forces of Storage and Consumption

Behavioral studies and recent empirical research suggest higher levels of inventory on hand can lead consumers to increase consumption. Inventory on hand is therefore posited to exert two countervailing forces on the probability of purchase incidence. First, higher levels of inventory reduce the likelihood of purchase as the consumer feels less pressure to buy. At the same time however, theory suggests higher levels of inventory may drive up the rate of consumption, thereby increasing the probability of incidence. We develop an empirical model that explicitly captures these two effects. The elasticity of purchase incidence with respect to inventory derived from the model is shown to capture these opposing forces in a simple and intuitive way. The analytical expression allows calculation of a threshold below (above) which the net effect is positive (negative). The model is estimated on ten product categories from the Stanford Market Basket database and is shown to fit better than both the standard nested logit approach and an alternative formulation developed by Ailawadi and Neslin (1998). The threshold values have plausible magnitudes and are intuitive across categories: butter, margarine and crackers have relatively low thresholds implying that inventory build up does not drive consumption; ice cream and soft drinks have relatively large thresholds (below which the inventory pressure to consume more outweighs the effect to delay purchase). Implications for retail management are discussed. --Choice Models,Consumption,Inventory,Purchase Incidence

Who Benefits from Reducing the Cost of Formality? Quantile Regression Discontinuity Analysis

This paper studies the effects of increasing formality via tax reduction and simplification schemes on micro-firm performance. It uses the 1997 Brazilian SIMPLES program. We develop a simple theoretical model to show that SIMPLES has an impact only on a segment of the micro-firm population, for which the effect of formality on firm performance can be identified, and that can be analyzed along the single dimensional quantiles of the conditional firm revenues. To estimate the effect of formality, we use an econometric approach that compares eligible and non-eligible firms, born before and after SIMPLES in a local interval about the introduction of SIMPLES. We use an estimator that combines both quantile regression and the regression discontinuity identification strategy. The empirical results corroborate the positive effect of formality on microfirms' performance and produce a clear characterization of who benefits from these programs.Formality, Micro-firms, Quantile regression, Regression discontinuity

Land taxes in a Latin American context

Since Henry George (1839-1897) economists have been arguing that a tax on unim- proved land is an ideal tax on e¢ ciency grounds. Output taxes, on the other hand, have distortional e¤ects on the economy. This paper shows that under asymmetric information output tax might be used along with land tax in order to implement the optimal taxation scheme in a Latin-American context, i.e., in an economy with imperfect land-rental market, non-agricultural land use and non-revenue objectives of land taxation. Also, we show that: (i) schemes based on land taxes alone might not be implementable; and (ii) tax evasion is more acute among large landholders.Optimal taxation, tax evasion, land use.

Capacitor and method of making same Patent

Capacitor fabrication by solidifying mixture of ferromagnetic metal particles, nonferromagnetic particles, and dielectric materia

New Species of Siparuna (Siparunaceae) IV

A new species of Siparuna (Siparunaceae), S. ficoides, is described, illustrated, and placed in a phylogenetic context based on morphological and DNA sequence data. The species, which is a monoecious subcanopy tree, is known from three collections made near Manaus, Brazil (two from the same tree), and one in the state of Bolivar, Venezuela.Se describe y se ilustra una nueva especie de Siparuna (Siparunaceae), S. ficoides, ademas se la ubica en un contexto filogenetico basado en datos morfologicos y en sequencias de DNA. Esta nueva especie es un arbol monoico de subdosel, de la cual se han registrado tres colecciones cerca de Manaos, Brasil (dos del mismo arbol) y una coleccion en el Estadod e Bolivar, Venezuela

Testing competing explanations for the inverse productivity puzzle

We use plot-level data from ICRISAT to assess competing explanations for an old empirical regularity - the inverse relationship between land productivity and farm size. The presence of farmers who simultaneously crop multiple plots with di¤erent sizes is used to test (and reject) explanations based on household heterogeneity. The panel nature of the data is explored to test (and refuse) explanations based on plot fixed characteristics. We are then left with explanations based on time-varying plot features or measurement errors in the plot size. Theoretically, the input choices should reflect both plot-specific features and the true plot size. Empirically, the inverse relationship vanishes when we control for input use.Development, farm size, productivity.

Challenging Small-scale Farming, A Non-parametric Analysis of the (Inverse) Relationship Between Farm Productivity and Farm Size in Burundi

We use a nonparametric estimation of the production function to investigate the relation- ship between farm productivity and farming scale in poor smallholder agricultural systems in the north of Burundi. Burundi is one of the poorest countries in the world, with a predominant small scale subsistence farming sector. A Kernel regression is used on data of mixed cropping systems to study the determinants of production including different factors that have been identified in literature as missing variables in the testing of the inverse relationship such as soil quality, location and household heterogeneity. Household data on farm activities and crop production was gathered among 640 households in 2007 in two Northern provinces of Burundi. Four production models were specified each with different control variables. For the relatively small farms, we find clear evidence of an inverse relationship. The relatively large farms show a different pattern. Returns to scale are found to be farm scale dependent. Parametric Cobb-Douglass models tend to over-simplify the debate on returns to scale because of not accounting for the different effects of large farms. Other factors that significantly positively affect production include the soil quality and production orientation towards banana or cash crop production. Production seems to be negatively affected by field fragmentation.inverse relationship, farm size, nonparametric, Burundi, Farm Management, Productivity Analysis,

A new solution approach to polynomial LPV system analysis and synthesis

Based on sum-of-squares (SOS) decomposition, we propose a new solution approach for polynomial LPV system analysis and control synthesis problems. Instead of solving matrix variables over a positive definite cone, the SOS approach tries to find a suitable decomposition to verify the positiveness of given polynomials. The complexity of the SOS-based numerical method is polynomial of the problem size. This approach also leads to more accurate solutions to LPV systems than most existing relaxation methods. Several examples have been used to demonstrate benefits of the SOS-based solution approach