Laura Cornelsen

The effect of rising food prices on food consumption: systematic review with meta-regression

Objective To quantify the relation between food prices and the demand for food with specific reference to national and household income levels. Design Systematic review with meta-regression. Data sources Online databases of peer reviewed and grey literature (ISI Web of Science, EconLit, PubMed, Medline, AgEcon, Agricola, Google, Google Scholar, IdeasREPEC, Eldis, USAID, United Nations Food and Agriculture Organization, World Bank, International Food Policy Research Institute), hand searched reference lists, and contact with authors. Study selection We included cross sectional, cohort, experimental, and quasi-experimental studies with English abstracts. Eligible studies used nationally representative data from 1990 onwards derived from national aggregate data sources, household surveys, or supermarket and home scanners. Data analysis The primary outcome extracted from relevant papers was the quantification of the demand for foods in response to changes in food price (own price food elasticities). Descriptive and study design variables were extracted for use as covariates in analysis. We conducted meta-regressions to assess the effect of income levels between and within countries on the strength of the relation between food price and demand, and predicted price elasticities adjusted for differences across studies. Results 136 studies reporting 3495 own price food elasticities from 162 different countries were identified. Our models predict that increases in the price of all foods result in greater reductions in food consumption in poor countries: in low and high income countries, respectively, a 1% increase in the price of cereals results in reductions in consumption of 0.61% (95% confidence interval 0.56% to 0.66%) and 0.43% (0.36% to 0.48%), and a 1% increase in the price of meat results in reductions in consumption of 0.78% (0.73% to 0.83%) and 0.60% (0.54% to 0.66%). Within all countries, our models predict that poorer households will be the most adversely affected by increases in food prices. Conclusions Changes in global food prices will have a greater effect on food consumption in lower income countries and in poorer households within countries. This has important implications for national responses to increases in food prices and for the definition of policies designed to reduce the global burden of undernutrition.

What Happens to Patterns of Food Consumption when Food Prices Change? Evidence from A Systematic Review and Meta‐Analysis of Food Price Elasticities Globally

Recent years have seen considerable interest in examining the impact of food prices on food consumption and subsequent health consequences. Fiscal policies targeting the relative price of unhealthy foods are frequently put forward as ways to address the obesity epidemic. Conversely, various food subsidy interventions are used in attempts to reduce levels of under-nutrition. Information on price elasticities is essential for understanding how such changes in food prices affect food consumption. It is crucial to know not only own-price elasticities but also cross-price elasticities, as food substitution patterns may have significant implications for policy recommendations. While own-price elasticities are common in analyses of the impact of food price changes on health, cross-price effects, even though generally acknowledged, are much less frequently included in analyses, especially in the public health literature. This article systematically reviews the global evidence on cross-price elasticities and provides combined estimates for seven food groups in low-income, middle-income and high-income countries alongside previously estimated own-price elasticities. Changes in food prices had the largest own-price effects in low-income countries. Cross-price effects were more varied and depending on country income level were found to be reinforcing, undermining or alleviating own-price effects.

Why fat taxes won't make us thin.

Increasing prevalence of overweight and obesity has led policy-makers to consider health-related taxes to limit the consumption of unhealthy foods and beverages. Such taxes are currently already in place in countries in Europe (e.g. Hungary, France and Finland) and in various states in the USA. Although these taxes are possibly efficient in reducing by a small amount the consumption of targeted products if the tax is fully transmitted to the consumer, there is too little available evidence on what will be consumed instead and whether these food substitutions undermine the hoped-for health benefits of the tax. We also know very little on how the food supply side will respond and what overall impact this will have. Without a proper appreciation of the potential indirect impacts we do not know the overall impact of taxes foods on unhealthy foods and beverages and further that there is a very real possibility that they may not be beneficial for health after all.

Impact of the smoking ban on the volume of bar sales in Ireland – evidence from time series analysis

This paper is the first to estimate the economic impact of a comprehensive smoking ban in all enclosed public places of work, on bars in Ireland. The demand in bars, represented by a monthly index of sales volume, is explained by relative prices in bars, prices of alcohol sold in off-licences and the aggregate retail sales (ARS) as a proxy for general economic activity and incomes. The smoking ban is included into the model as a step dummy and the modelling is done using ARIMAX strategy. The results show a reduction in the volume of sales in bars by -4.6% (p<0.01) following the ban.

Is roll-your-own tobacco substitute for manufactured cigarettes: evidence from Ireland?

BACKGROUND When tax policies increase tobacco prices some smokers may switch to smoking cheaper roll-your-own (RYO) tobacco. To reduce the harm from smoking, this substitution effect should be avoided. This study analyses whether RYO tobacco is a substitute for manufactured cigarettes (MCs) in Ireland, a country with relatively high price for both products. METHODS Data on duty-paid consumption of RYO tobacco from 1978 to 2011 are used to estimate the demand by applying seemingly unrelated regression and error correction models. Covariates include prices of tobacco in Ireland and in the UK, income and a variable describing tobacco-related health policies. RESULTS We failed to find evidence of RYO tobacco being a substitute for MC due to price differences. However, an increase in incomes (1%) is associated with a reduction in the consumption of RYO tobacco (-0.4%), which can be due to substitution towards MCs in addition to quitting or cutting back. Also, an increase in the price of RYO tobacco (1%) is associated with a reduction in its consumption (-1%). CONCLUSIONS Increasing prices via taxation is an effective way of reducing the consumption of RYO tobacco but due to associations between RYO tobacco smoking and lower incomes, these policies should be accompanied by measures aimed at helping smokers to quit.

Systematic review and meta-analysis of the economic impact of smoking bans in restaurants and bars

AIMS To review systematically the literature on the economic impact of smoking bans in bars and restaurants and provide an estimate of the impact size using meta-analysis. METHODS Studies were identified by systematic database searches and screening references of reviews and relevant studies. Google and web-pages of tobacco control agencies were also searched. The review identified 56 studies using absolute sales, sales ratio or employment data and employing regression methods to evaluate the impact of smoking bans in the United States, Australia or in countries in South America or Europe. The meta-analysis included 39 comparable studies, with 129 cases identified based on the outcome measure, scope of the ban, type of establishment and geographical location. Methodological quality was assessed based on four pre-determined criteria. Study and case selection and data extraction were conducted independently by two researchers. RESULTS Random-effects meta-analysis of all cases showed no associations between smoking bans and changes in absolute sales or employment. An increase in the share of bar and restaurant sector sales in total retail sales was associated with smoking bans [0.23 percentage-points; 95% confidence interval (CI) 0.08-0.375]. When cases were separated by business type (bars or restaurants or wider hospitality including bars and restaurants), some differential impacts emerged. CONCLUSIONS Meta-analysis of the economic impact of smoking bans in hospitality sector showed overall no substantial economic gains or losses. Differential impacts were observed across individual business types and outcome variable, but at aggregate level these appear to balance out.

Change in non-alcoholic beverage sales following a 10-pence levy on sugar-sweetened beverages within a national chain of restaurants in the UK: interrupted time series analysis of a natural experiment

Background This study evaluates changes in sales of non-alcoholic beverages in Jamie’s Italian, a national chain of commercial restaurants in the UK, following the introduction of a £0.10 per-beverage levy on sugar-sweetened beverages (SSBs) and supporting activity including beverage menu redesign, new products and establishment of a children’s health fund from levy proceeds. Methods We used an interrupted time series design to quantify changes in sales of non-alcoholic beverages 12 weeks and 6 months after implementation of the levy, using itemised electronic point of sale data. Main outcomes were number of SSBs and other non-alcoholic beverages sold per customer. Linear regression and multilevel random effects models, adjusting for seasonality and clustering, were used to investigate changes in SSB sales across all restaurants (n=37) and by tertiles of baseline restaurant SSB sales per customer. Results Compared with the prelevy period, the number of SSBs sold per customer declined by 11.0% (−17.3% to −4.3%) at 12 weeks and 9.3% (−15.2% to −3.2%) at 6 months. For non-levied beverages, sales per customer of children’s fruit juice declined by 34.7% (−55.3% to −4.3%) at 12 weeks and 9.9% (−16.8% to −2.4%) at 6 months. At 6 months, sales per customer of fruit juice increased by 21.8% (14.0% to 30.2%) but sales of diet cola (−7.3%; −11.7% to −2.8%) and bottled waters (−6.5%; −11.0% to −1.7%) declined. Changes in sales were only observed in restaurants in the medium and high tertiles of baseline SSB sales per customer. Conclusions Introduction of a £0.10 levy on SSBs alongside complementary activities is associated with declines in SSB sales per customer in the short and medium term, particularly in restaurants with higher baseline sales of SSBs.

3rd Annual Conference of the Leverhulme Centre for Integrative Research on Agriculture and Health (LCIRAH), Developing methods in agriculture and health research, London, 13-14 June 2013

Agriculture and health interact in complex ways via food systems and nutrition, creating positive and negative synergies, which differ according to economic, political and environmental contexts, but particularly affecting the lives of vulnerable populations in low-income countries. Research in these subjects has historically proceeded in relative isolation, with different disciplines applying distinct methods to generate knowledge and inform sector-based policy and practice. This segregated working is not beneficial if research is to inform the design and implementation of programs and policies that aim to fully and sustainably address the nexus of agriculture and health. Encouragingly, policy and programmatic initiatives, as well as research endeavours, have been increasingly attentive to the linkage of agriculture and health as a method for improving nutritional status and health (Masset et al. 2012). More and better multi-sectoral action will be necessary, however, to reduce the harms and enhance the benefits of the agriculture-health relationship, and research increasingly needs to engage with this complex picture if findings are to remain relevant to policy and practice. In response to this interdisciplinary challenge, the Leverhulme Centre for Integrative Research on Agriculture and Health (LCIRAH) was established in 2010 with a grant from the Leverhulme Trust to develop “unifying approaches and methodologies for understanding the relationship between agricultural production and population health, and the factors which drive them both”an agri-health research agenda (www.lcirah.ac.uk). Since its inception, LCIRAH has hosted three international conferences endeavouring to bring together experts from different sectors to share perspectives and explore integrated inter-disciplinary approaches to global agri-health challenges. In 2011, the first conference, organised with the International Food Policy Research Institute (IFPRI), had a strong focus on agri-health metrics, with scholars presenting work on ways in which metrics and methods can cross disciplines to fill knowledge gaps. The conference found a potentially huge benefit in promoting the understanding and utilization of different methods across disciplines to move the agri-health research agenda forward. The second conference, in 2012, J. Harris :M. Bruce : E. Cavatorta : L. Cornelsen :B. Hasler : R. Green : E. H.Morgan : S. Stevano :H. L.Walls :K. Cunningham Leverhulme Centre for Integrative Research on Agriculture and Health (LCIRAH), London, UK

Cross-sectional study of drivers of animal-source food consumption in low-income urban areas of Nairobi, Kenya

BackgroundMalnutrition, including undernutrition and micronutrient deficiencies is a chronic problem in most developing countries. Animal-source foods (ASFs) provide essential sources of proteins and micronutrients, yet little is known about ASF consumption patterns or household preferences towards animal-source products among low-income populations. This is particularly critical for malnourished children for whom even small increases in consumption could help improve nutrition and health outcomes. This study analysed both the demand as well as the drivers and barriers for ASF consumption among households in two low-income areas in Nairobi, Kenya.MethodsData on ASF expenditures and quantities purchased in the previous week, and reasons for consuming or not consuming ASFs were collected in a cross-sectional study from 205 randomly selected households in Korogocho and Dagoretti settlements. Self-reported reasons for consuming or not-consuming ASFs were described. Demand for ASFs was estimated using the Almost Ideal Demand System to provide measures of demand elasticity for changes in food prices and expenditures.ResultsOn average households purchased 48 grams of ASFs, including fresh milk, per week per household member. Expenditure on ASFs counted for 38% (520 Kenyan Schillings) of the overall food expenditure of which, on average, 48% was spent on fresh milk. Price was the most commonly self-reported barrier for consumption, while taste was reported as the main driver for consumption. The perceived nutritional value was an important driver for consuming more commonly purchased ASFs (beef, eggs, fish and milk). For less commonly purchased ASFs (pork, sausages, sheep and goat meat, offal) taste, access and tradition were given as main reasons for not consuming. Estimated demand elasticities indicated that increases in total food expenditure would lead to greatest increase in the demand for beef meat. Price reductions would increase the demand relatively more for fish, other meats and dairy.ConclusionsFor most ASFs better affordability would be a clear driver to increase the consumption. However, to increase the variety and quantity of ASFs eaten, other policies targeting improvements in physical access, food safety and consumer education on nutritional values and cooking methods should be considered.

Is a tax on sugary drinks too bitter to swallow

Briggs and colleagues’ study is a useful addition to the evidence on the potential health impact of taxes on sugar sweetened drinks.1 But to convince policy makers of the effectiveness of such taxes we urgently need experimental studies that allow stronger causal inference than modelled projections based on historic consumption data. Furthermore, non-economic determinants of food consumption such as …