Variability in agricultural productivity and rural household consumption inequality: Evidence from Nigeria and Uganda

This paper uses multiple rounds of panel data to assess the distributional implications of the variability in agricultural productivity in Nigeria and Uganda. It uses both a conventional decomposition and a regression‐based inequality decomposition approach to estimate the impact of climate‐induced variability in agricultural productivity. To mitigate the endogeneity associated with unobserved time‐invariant and time‐variant household fixed effects, we use rainfall shocks as a proxy for estimating the exogenous variability in agricultural productivity that affects consumption. Results suggest that a 10% increase in the variability of agricultural productivity tends to decrease household consumption by 38 and 52% on average for Nigeria and Uganda, respectively. Controlling for other factors, variability in agricultural productivity contributed to between 25% and 43% of consumption inequality between 2010 and 2015 for Nigeria; and 16% and 31% of consumption inequality between 2009 and 2011 for Uganda. We also show that variability in agricultural productivity increases changes in consumption inequality over time.     

Isolation and agricultural productivity

This article examines the mechanisms that transmit isolation into productivity. In particular, we study the effect of isolation and transport infrastructure on welfare and agricultural productivity in the case of Madagascar. Madagascar is a good case study given the bad shape of its infrastructure and therefore the significant variation in isolation. Based on comprehensive household survey data combined with a census of communes, we discover a strong poverty–isolation relationship. Further we find the inverse relationship between agricultural productivity and isolation to be surprisingly strong. We isolate the following reasons why productivity might decline with isolation: (i) transportation‐induced transaction costs, (ii) the inverse relationship between plot size and productivity, (iii) increasing price variability and extensification onto less fertile land, and (iv) insecurity.     

Farmer management of production risk on degraded lands: the role of wheat variety diversity in the Tigray region, Ethiopia

This article investigates the effects of wheat genetic diversity and land degradation on risk and agricultural productivity in less favored production environments of a developing agricultural economy. Drawing production data from a household survey conducted in the highlands of Ethiopia, we estimate a stochastic production function to evaluate the effects of variety richness, land degradation, and their interaction on the mean and the variance of wheat yield. Ethiopia is a center of diversity for durum wheat and farmers manage complex variety mixtures on multiple plots. Econometric evidence shows that variety richness increases farm productivity. Variety richness also reduces yield variability but only for high levels of genetic diversity. Simulations with estimated parameters illustrate how planting more diverse durum wheat varieties on multiple plots contribute to improving farmer's welfare.     

Productivity in Indonesian agriculture: Impacts of domestic and international research

Total factor productivity growth contributed 38% of Indonesia's agricultural output growth from the mid-1970s to the mid-2000s. This study uses time series data analysed with an error correction mechanism to examine the contribution that Indonesian publicly funded agricultural research made to this outcome, allowing for other possible determinants of productivity growth, including international agricultural research, extension, government price policy and weather. The results imply a 27% real annual rate of return from a marginal increase in Indonesian agricultural research expenditure. Indonesia's public agricultural research explains virtually all of its agricultural total factor productivity growth between 1975 and 2006.     

Measuring farm productivity under production uncertainty

This research introduces a novel empirical application to the assessment of farm productivity growth. While the existing research on productivity change has primarily focussed on ex post output observations, it has been shown that ignoring production uncertainty can lead to unreliable results. Using a state-contingent framework to represent the stochastic production environment, we extend the recent line of research that merged the state-contingent approach and efficiency measurement to productivity change using the Malmquist and Luenberger productivity indices. Using a balanced panel of 117 arable crop farms surveyed in 2011 and 2015, we show through the study results that productivity decreased, with technological regress being the major source of productivity change. Differences in productivity change between nonstochastic and stochastic modelling show the relevance to consider the state-contingent framework when assessing farms' productivity.     

Measuring public agricultural research and extension and estimating their impacts on agricultural productivity: new insights from U.S. evidence

This article provides new estimates of the marginal product of public agricultural research and extension on state agricultural productivity for the U.S., using updated data and definitions, and forecasts of future agricultural productivity growth by state. The underlying rationale for a number of important decisions that underlie the data used in cost‐return estimates for public agricultural research and extension are presented. The parameters of the state productivity model are estimated from a panel of contiguous U.S. 48 states from 1970 to 2004. Public research and extension are shown to be substitutes rather than complements. The econometric model of state agricultural TFP predicts growth rates of TFP for two‐thirds of states that is less than the past trend rate. The results and data indicate a real social rate of return to public investments in agricultural research of 67% and to agricultural extension of 100+%. The article concludes with guidance for TFP analyses in other countries.     

马歇尔分成租佃制真的导致土地资源利用“无效率”——基于20世纪30年代卜凯农家调查资料的检验

由分成租佃制导致土地产出减少的"马歇尔无效率"一直是学术界研究的热点话题。许多实证研究尝试通过土地产出率、劳动—土地比率以及地租等对这一理论的正确性进行检验,但这些都无法体现经济学理论中资源利用遵循边际均等法则。本文通过对国内外文献关于分成租佃制理论的系统梳理,基于佃农收入最大化的目标,对佃农理论模型进行修正。在此基础上,结合20世纪30年代卜凯农家调查资料,实证检验了分成租佃制下土地资源利用效率问题。研究结果表明:(1)在土地同质的条件下,分成佃农、定额佃农和自耕农的土地边际生产力并不存在显著差异,分成租佃制下土地资源利用是有效率的。(2)土地边际生产力的相对差异,一方面导致土地租佃比率发生变化,另一方面通过租佃制度进行灵活的规模调整,从而实现土地资源配置的优化。     

Sense and sustainability revisited: the limits of total factor productivity measures of sustainable agricultural systems

Many economists have advocated and applied total social factor productivity (TSFP) (i.e., total factor productivity estimated with both market and non‐market inputs and externalities, and with all factors valued at social prices) as a single all‐embracing measure of agricultural sustainability. This paper reviews the conceptual and practical issues in measuring TSFP and shows that no one measure alone will be theoretically or empirically robust as an indicator of sustainability. TSFP is a conceptually flawed measure since inclusion of non‐market inputs and outputs and social price‐based valuation, in most cases, violates the theoretical basis underlying those estimates. Trends in TSFP also have limited value in diagnosing the nature of sustainability problems, unless changes in productivity are related to underlying changes in technology, human and physical infrastructure, and indicators of resource quality. More attention needs to be given to defining key indicators of agro‐ecosystem health and relating these measures to trends in productivity. This analysis must be sufficiently disaggregated and for a long enough time period to allow for spatial and temporal variability inherent in agricultural production. Secondary data at the district level on both conventional inputs and outputs and resource quality have recently allowed more quantitative estimates of sustainability and its causes. With limited data, yield growth decomposition analysis can often be used to provide valuable insights into sustainability problems. Meanwhile, there is a need to invest in long‐term experimental and panel surveys of farmers and their fields for key production systems in order to provide long‐term data that will allow full productivity accounting, using more formal statistical procedures. Regardless of the approach selected, the findings of this paper strongly suggest a need for economists, agronomists and soil scientists to collaborate in integrating approaches in order to provide more robust and informative measures of sustainability.     

Do Formula or Competitive Grant Funds Have Greater Impacts on State Agricultural Productivity?

This article examines the impact of public agricultural research and extension on agricultural total factor productivity at the state level. The objective is to establish whether federal formula or competitive grant funding of agricultural research has a greater impact on state agricultural productivity. A pooled cross-section time-series model of agricultural productivity is fitted to annual data for forty-eight contiguous states over 1970–1999. Our results show that public agricultural research and agricultural extension have statistically significant positive impacts on state agricultural productivity. In addition, Hatch formula funding has a larger impact on agricultural productivity than federal competitive grant funding, and a reallocation of Hatch formula funds to competitive grant funding would lower agricultural productivity. This seems unlikely to be a socially optimal policy. Furthermore, from a cost–benefit perspective, our study shows that the social marginal annualized real rate of return to public resources invested in agricultural research is 49–62%, and to public agricultural extension, the rate is even larger.     

The impacts of climate change on Australia and New Zealand: a Gross Cell Product analysis by land cover*

This paper examines the newly constructed geographically scaled economic output measure, Gross Cell Product (GCP), of Australia and New Zealand to quantify the impacts of climate change in the region. The paper discusses advantages of using the GCP instead of the Gross Domestic Product. The paper reveals that the GCP falls sharply as temperature increases in the region. A 1°C increase in temperature would decrease the productivity with an elasticity of ?2.4. A 1 per cent decrease in precipitation would decrease productivity with an elasticity of ?2.3. However, forest vegetation on the coasts will benefit from initial warming. We find that the changes in climate means are potentially more harmful than changes in climate variability. In the long term, a 3.4° warming coupled with 6.6 mm decrease in rainfall would decrease the GCP by 34 per cent by 2060. The damage is largely accounted for by population effects. The paper confirms that Australia is highly constrained by climate and geographic factors.     

Is research on marginal lands catching up? The case of unfavourable wheat growing environments⋆

It is widely believed that the Green Revolution had very little effect in unfavourable or marginal environments. Many researchers have been concerned about the slow progress of technical change in marginal environments and the level of research resources allocated to these areas. This paper provides empirical evidence that there has been significant growth in wheat yield potential in marginal environments, especially during the post‐Green Revolution. International yield trial data, covering all major wheat growing environments from 1964 to 1999, were used in estimating the growth in wheat yield potential and changes in yield variability. The global database on wheat varietal adoption and yield gains based on estimated wheat yield growth rates were used to determine production increases due to wheat breeding research. Results show greater progress in shifting the wheat yield frontier in marginal areas, particularly in drought and high temperature environments. Furthermore, yield variability in marginal environments has notably declined, while it has increased slightly in favourable environments. While initial gains came from crossover of varieties from favourable environments, targeted breeding efforts have contributed significantly to more recent productivity growth in marginal environments. Increased production from marginal environments accounted for around 25% of the total wheat production increase in 1997. These findings show greater progress in wheat research and the huge potential of improving wheat productivity in unfavourable environments.     

Price and yield effects of spill-overs in international agricultural research: evidence from ICRISAT and Australia

International agricultural research aimed at improving productivity in developing countries also has spill-over effects on developed countries. Research that affects the supply of commodities is also likely to affect the world price of tradeable commodities. In this paper, the effects of spill-overs to Australia from successful cost-reducing research into sorghum and chickpeas at die International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) aimed at developing countries are assessed. Genetic materials developed and distributed through ICRISAT are used in Australia to increase productivity. The price-reducing effects of successful research are incorporated into the analysis of spill-over impacts on productivity. The net effects on welfare for producers and consumers of sorghum and chickpeas in Australia and the Rest of the World (ROW) are identified. The consequences of the impacts are discussed and the implications for further funding of international agricultural research are also discussed.     

Payoffs from research and development along the Australian food value chain: a general equilibrium analysis

The payoffs and distribution of payoffs from research and development (R&D) along the food value chain depend on many interacting economic factors. To quantify these, we have developed a general equilibrium model of the Australian economy with detailed farming, processing and marketing information. We use the model to assess potential payoffs and distributions from various R&D scenarios that lead to demand expansion and productivity improvement. We find that productivity improvement caused by R&D is unambiguously beneficial to the whole economy while the benefits of export or domestic market demand expansion mainly accrue to the primary producers and processing industry, when the economy is at full employment. Also, productivity improvement from R&D on‐farm may benefit processors while improvements postfarm may benefit farmers.     

Broadacre farm productivity and profitability in south‐western Australia

This paper examines broadacre farm performance in south‐western Australia. This region has experienced pronounced climate variability and volatile commodity prices since the late 1990s. Relationships between productivity and profitability are explored using panel data from 47 farms in the study region. The data are analysed using nonparametric methods. By applying the Fare‐Primont index method, components of farm productivity and profitability are measured over the period 1998–2008. Growth in productivity is found to be the main contributor of profitability. Gains in efficiency and technical change are identified as jointly and similarly important in their contribution to total factor productivity for the farm sample in the region from 1998 to 2008. However, across environments, efficiency gains play an increasingly important role in influencing productivity as growing season rainfall increases. We conclude that R,D&E that delivers further improvement in technical efficiency and technical change is needed to support the profitability of farms across the study region.     

On the Relationship between the Student–Advisor Match and Early Career Research Productivity for Agricultural and Resource Economics Ph.D.s

We use a unique data set on students receiving their Ph.D.s from top-ranked agricultural and resource economics programs to investigate how the ranking of a student's dissertation advisor affects his or her early career research productivity. After controlling for program reputation, we find that the higher the relative research productivity of a student's dissertation advisor the greater the student's early career research productivity. Allowing the estimated effects of advisor rank to vary with program reputation suggests that students from lower-ranked programs working with relatively more prominent advisors outperform their peers at highly ranked programs working with less prominent advisors.     

BIASES IN RESEARCH: THE CASE OF RUBBER GROWING IN MALAYSIA

This paper measures the impact of technological progress in Malaysian rubber growing and tests the hypothesis that past research has been biased in favour of raising the productivity of capital rather than labour. It also demonstrates the methodological usefulness, in relation to a long-lived perennial crop, of separating embodied from disembodied technical change. The analysis indicates that research leading to new embodied technology has not been biased since it has raised the productivity of all input factors at about the same rate over time. However, disembodied technological change has not shifted the production hypersurface in an unambiguously neutral fashion. These results are especially pertinent to the debate about the future direction of rubber growing research.     

城市基础设施建设对土地产出率的影响及其地区差异

研究目的：研究基础设施建设对城市土地产出率的影响及其地区间的差异。研究方法：根据集聚经济原理构建城市土地产出率模型,利用全国城市面板数据检验基础设施对土地产出率的贡献。研究结果：控制了实物资本和劳动投入密度等土地产出率的基本决定因素后,基础设施资本密度是土地产出率的重要贡献因素,各项基础设施都有独立的贡献;基础设施资本存量在西部地区的增长对城市土地产出率作用最大,在东部次之,在中部地区的影响不显著。研究结论：各地应根据自身基础设施的完善程度和边际收益有选择地推进基础设施建设,达到节约土地和促进增长的综合目的。     

The Creation and Spread of Technology and Total Factor Productivity in China's Agriculture

The overall goal of this study is to create a framework for assessing the trends of China's national and international investment in agricultural research and to measure its impact on total factor productivity. The main methodological contribution is to provide more convincing measures of crop–specific technologies from China's national research program and of those imported from the international agricultural research system. Our results find that from 1980 to 1995, China's total factor productivity for rice, wheat, and maize grew rapidly and new technology accounts for most of the productivity growth.     

The public R&D and productivity growth in Australia's broadacre agriculture: is there a link?

This paper investigates the dynamic relationships between research and development (R&D) expenditure and productivity growth in Australian broadacre agriculture using aggregate time series data for the period 1953 to 2009. The results show a cointegrating relationship between R&D and productivity growth and a unidirectional causality from R&D to TFP (total factor productivity) growth in Australian broadacre agriculture. Using the dynamic properties of the model, data from beyond the sample period are analysed by employing the variance decomposition and the impulse response function. The findings reveal that R&D can be readily linked to the variation in productivity growth beyond the sample period. Furthermore, the forecasting results indicate that a significant out‐of‐sample relationship exists between public R&D and productivity in broadacre agriculture.     

COINTEGRATION,AND CAUSALITY: EXPLORING THE RELATIONSHIP BETWEEN AGRICULTURAL AND PRODUCTIVITY

This study investigates the causal relationships between total factor productivity (TFP) and explanatory variables, such as public sector agricultural extension, farmer education, private sector patents and the weather. Cointegration and Granger causality tests are applied to the UK data which were used by Hallam (1990). Unlike Hallam, we find that there is a relationship between research spending and productivity. The same methodology is applied to new data for ten EC countries and the USA. In all cases there is evidence of a long run relationship between TFP and. Pooling the data for the ten EC countries and the USA, and then testing for causality shows that expenditures are Granger prior to TFP and that TFP is also Granger prior to expenditures. This result agrees with Pardey and Craig's (1989) US study.