Is the Engel curve approach viable in the estimation of alternative PPPs?

Conventional estimates of purchasing power parities (PPP) rely on cross-country price data. Using Engel curves, Almås (Am Econ Rev 102:1093–1117, 2012) was, however, able to show that PPPs contain substantial bias. Since constructing conventional estimates is expensive and time consuming, Almås’ idea of employing Engel curves is welcome. This article examines the viability of the Engel curve approach to PPP and its sensitivity to differences in relative prices and preferences by estimating Engel curves not only between countries but also for regions within a given country. My empirical evidence from the United States and Norway suggests that the differences can be problematic, but not sufficiently to discredit the new methodology. A pragmatic approach to PPP estimation between countries that are different is to compute a PPP band, rather than a point estimate. I present a practical example of this using expenditure data from 2001, which yields a band for NOK and US dollar.     

HOW TO MEASURE LIVING STANDARDS AND PRODUCTIVITY

I set out a general algorithm for calculating true cost‐of‐living indices when demand is not homothetic and when the number of products may be large. The non‐homothetic case is the important one empirically (Engel's Law). The algorithm can be applied in both time series and cross section. It can also be used to estimate true producer price indices and Total Factor Productivity in the presence of input‐biased economies of scale and technical change. The basic idea is to calculate a chain index of prices but with actual budget (cost) shares replaced by compensated shares, i.e. what the shares would have been if consumers (firms) faced actual prices but their utility (output) were held constant at some reference level. The compensated shares can be derived econometrically from the same data as are required for the construction of conventional index numbers. The algorithm is illustrated by applying it to estimating true PPPs for 141 countries and 100 products within household consumption, using data from the World Bank's latest International Comparison Program.     

Income Elasticities at different price vectors

Cross-country data are used to evaluate the income elasticities of the demand for ten broad groups of goods at two different price vectors: the observed prices of separate countries and the geometric means of these prices across all countries. The major effect is on the income elasticity of the demand for food; using observed rather than geometric mean prices results in lower elasticity values for the more affluent countries.     

Price Levels and Economic Growth: Making Sense of Revisions to Data on Real Incomes

The price surveys from the 2005 International Comparison Program (ICP) imply substantially lower levels of GDP at purchasing power parity (PPP) for many developing countries than prior estimates. While some observers have questioned the data, this paper argues that the pattern of changes in PPPs between ICP rounds makes economic sense. Consistently with the original Balassa–Samuelson model, more rapidly growing economies experienced steeper increases in their PPPs relative to official exchange rates. This effect was even stronger for poor countries. Taking account of this effect would reduce the need for such large data revisions when new ICP data become available.     

THE STRUCTURE OF HOUSEHOLD SPENDING IN SOUTH AMERICAN CITIES: INDEXES OF DISSIMILARITY AND CAUSES OF INTER-CITY DIFFERENCES

Household budget data collected in 1966–1971 in eleven cities in six South American countries are used to define individual mean budget structures (means of budget shares across households). These structures are then compared by indexes of dissimilarity, calculated for the entire budget and also for major components: food, animal protein foods, nonfood, and housing and clothing. Differences among cities in real income account for much of the difference in the share of the consumer budget devoted to food, which in turn is a principal source of overall budget dissimilarity. Within the food and nonfood budgets separately, income is of somewhat less importance; prices and preferences become more significant. Budget structures tend for this reason to be similar for cities in the same country. The structure of nonfood spending also varies markedly between coastal and interior cities, largely because of differences in housing costs. The available price data account for dissimilarities which depend on the price of a single large category of spending, but they do not help explain structural differences involving many categories: prices seem more important for nonfood than for food expenditures. Regression analysis is used to weigh the importance of each variable contributing to dissimilarity.     

Constructing Bounds on Per Capita Income Differentials across Countries

The results of purchasing power parity (PPP)-based comparisons of income across countries can be quite sensitive to the choice of index number formula. Tighter bounds on per capita income differentials can be constructed either by assuming homothetic preferences, or by estimating a demand system. Both approaches are used to construct bounds on per capita income differentials across the OECD countries. The paper concludes by discussing the strengths and weaknesses of each approach.
JEL Classification C 43; F 31; O 47     

A dynamic model of demand for Mediterranean tourism

A dynamic econometric model was specified in order to estimate tourism consumption changes by Northern European countries and the USA for major Mediterranean destinations. The model employed a flexible framework for modelling short-term dynamics as well as the long run effects of a range of variables of specific interest to the countries considered. The estimated model provided useful information for tourism demand. The income elasticities demonstrated considerable differences in tourism demand preferences between origin countries and between traditional and newly developing destinations. The own and substitute price elasticities indicated the importance of effective prices in determining tourism receipts of the destinations.     

Changes in income distribution and welfare from greater immigration of unskilled workers

This paper considers the consequences of greater immigration of unskilled labor on income distribution and welfare in the receiving country. To address these issues, both the sending and receiving countries are represented in a static general equilibrium model which distinguishes between skilled and unskilled labor and which allows prices to be determined endogenously. In this framework an inflow of unskilled labor is likely to reduce wages of unskilled labor, but whether capital or skilled labor benefits depends upon demand elasticities, elasticities of substitution in production, and differences across countries in the productivity of unskilled labor. National welfare in the receiving country is likely to rise, to the extent that the relative price of importable goods falls, non-residents already in the country receive lower wages, immigrants receive lower wages than those paid to domestic workers, and immigrants cause little increased demand for public services and transfer programs.     

A Note on Production Efficiency in Oligopolistic Trade Models

In a two‐country segmented markets model with homogeneous product Cournot oligopoly we show that production efficiency improves in the free‐trade regime compared to autarky, if autarky price in each country is lower than both the post‐trade prices—which holds, for example, when preferences are identical. The result holds irrespective of the demand structure, number, and cost distribution of firms in the two countries. The improvement in production efficiency lowers average cost of production which, for some parameterizations, gives rise to higher aggregate profits for all countries in the free‐trade regime (compared to autarky). Though free trade (zero tariffs) improves production efficiency from autarky (prohibitive tariffs), freer trade is not always associated with greater production efficiency.     

Purchasing Power Parity When Prices Are I(2)

This paper examines the purchasing power parity (PPP) hypothesis over the modern float using data on 15 OECD currencies. Evidence is presented that suggests the price levels evolve as second-difference stationary processes, i.e., integrated of order two ( P₁– I (2)). A necessary condition for PPP when prices are I (2) is that prices are cointegrated across countries to an I (1) relative price. In general this relative price is not the same as the simple price ratio. For some of the relationships examined, this relative price level is cointegrated with the exchange rate, implying a long-run equilibrium between nominal exchange rates and prices.     

Consumer welfare effects of increased food and energy prices

In this study, the authors evaluated how much price changes in food and energy – two basic living expenditures competing for consumers’ budgets – would affect consumer welfare. We first estimated a US complete demand system to quantify the interdependent demand relationships among 11 categories of consumption expenditures. Among the estimates, the own price elasticities of both food and energy are relatively inelastic, a finding that explains the dynamics of the recent soaring food and energy prices. The estimated demand elasticities were then incorporated into the measurement of Hicksian compensating variation to analyse the consumer welfare effects of price changes in food and energy. The results indicated that an increase in food and energy prices would increase compensated expenditures or incur a substantial consumer welfare loss, creating an especially heavy burden for low income households.     

Internal Relative Price Stationarity in Long-Run Purchasing Power Parity

This study demonstrates that the joint relationship among domestic traded-goods prices, dometic nontraded-goods prices, foreign traded-goods prices, and foreign nontraded-goods prices is important to understanding rejections or confirmations of long-run PPP. This joint relationship is defined as the "cross-country internal relative price structure." For nine of the ten pairs of countries studied, the cross-country internal relative price structure is found to be stationary; thus, factors other than the influence of nontraded-goods prices must be responsible for the rejections of long-run PPP.     

Impact of oil price changes on Turkey’s exports

Substantial decline in oil prices observed since the second half of 2014 has brought forward discussions on the impact of oil prices on the external balance. This decline is expected to shift real income from oil exporter countries to oil importer countries. In this context, we study the effect of change in oil prices on Turkey’s exports taking into account the fact that Turkey’s export to oil exporting countries has approximately one-third share in total exports, while export to oil importing countries has a share of two-thirds. At the first step, we analyse the effect of oil prices on economic growth of trade partners of Turkey, where countries are grouped according to their net oil export position. We find that the effect of oil prices on different country groups’ growth is asymmetric. In the second stage, for two groups of countries, we estimate growth-export elasticity through Turkey’s export demand function. Finally, we calculate the net effect of oil prices on exports considering different income effects caused by oil price change on each country groups. Results indicate that the net effect of oil prices on the exports is limited given the current export shares.     

A Framework for the Simultaneous Measurement of Spatial Variation and Temporal Movement in Prices in a Heterogeneous Country: The Dynamic Household Regional Product Dummy Model

This paper contributes to the growing literature on spatial prices in large heterogeneous countries. While the literatures on spatial variation and temporal movement in prices have grown in parallel, this study marks a departure by providing a unified treatment and proposing a comprehensive framework that allows both approaches. The proposed model is based on twin extensions of the household version of the “country product dummy model” by allowing for a dynamic stochastic specification and interdependence of spatial prices of geographically adjacent regions. Tests of temporal stability and regional independence of the estimated spatial prices are proposed and applied in this paper. The paper shows that the introduction of an autoregressive error process of order one, AR(1), improves the efficiency of the estimates of parameters, urban‐rural and temporal price indices under certain conditions. The Indian application points to a rich potential for using the proposed framework in cross country comparisons such as the International Comparison Program (ICP) exercises.     

Re-evaluation of Welfare Changes during the Transition in Poland

The costs of shortages/rationing are not captured by standard consumer price indices. Thus the change in real GDP per capita is an over-estimate of welfare losses in transition economies. In this study virtual prices are used to calculate new cost of living indices, making it possible to construct more accurate pre-reform and post-reform welfare comparisons. The results for Poland using virtual prices show 62-84% decline in welfare over the transition 1987-92. This welfare loss is approximately one-third of the value obtained using actual prices.     

Pharmaceutical regulation under market integration through parallel trade

In this paper, I study the effect of parallel trade (cross-border resale of goods without the authorization of the manufacturer) on pharmaceutical regulation. Governments may restrict prices directly (price caps) or limit third-party payer reimbursement for the drug (reimbursement limits). I find that parallel trade may relax regulation in the source country of parallel imports under both instruments and intensify regulation in the destination country under a reimbursement limit. I also find that parallel trade may change regulatory preferences: under no parallel trade, both the source and destination country set price caps, and under parallel trade, the source country sets a price cap but the destination country sets a reimbursement limit, thereby enforcing a higher price cap in the South. This implies that drug prices are higher under parallel trade in both source and destination countries.     

City size and household food consumption: demand elasticities in Spain

Are food price elasticities different across city sizes? The aim of this article is to estimate expenditure and own-price elasticities for 10 aggregated food product groups using the Spanish Household Budget Survey for the year 2010. These products are the ones for which the survey provides information regarding prices and quantities, thus allowing the application of an Almost Ideal Demand System (AIDS) model with censored data. The estimation procedure allows not only comparisons to be made among households with different levels of income, but also the contribution of residence characteristics to variations in demand. The results confirm that the size of the city in which the household resides has a similar significant and relevant effect on consumption patterns as family income level. This is especially clear with own-price elasticities. In Spain, large central cities show a greater response to price changes than smaller cities or rural peripheral areas.     

The effects of price on household demand for food and calories in poor countries: are our databases giving reliable estimates?

Food price policy relies heavily on estimated price elasticities of food demand to help balance the nutritional and economic objectives in poor countries. Economists use either unit values (ratios of household expenditure to quantity purchased) or community prices (enumerated from vendors in local markets) as proxies for market prices when estimating price elasticities with household survey data. Biases are believed to result from using unit values, due to measurement error and quality effects, but evidence on this issue is lacking and even less is known about community prices. This article provides an empirical evidence from Vietnam, which suggests that economists should exercise caution when estimating price elasticities from household surveys. A 14-food demand system is estimated alternatively with unit values or community prices, and the elasticity of calories with respect to rice prices is calculated. This elasticity is more than twice as large (?0.54 versus ?0.22) when community prices are used rather than unit values. Hence, conclusions about the nutritional effects of rice price increases appear sensitive to data choices made by economists. More generally, this discrepancy suggests that the household survey databases commonly used by economists may not provide reliable estimates.     

Poverty Effects of Higher Food Prices: A Global Perspective

The spike in international food prices between 2005 and the first half of 2008 drew much attention to the vulnerability of the poor to such shocks. This paper provides a formal assessment of the direct and indirect impacts of higher prices of agricultural goods on global poverty using a representative sample of 63–93% of the developing world's population. To assess the direct effects, the paper uses domestic food price data between January 2005 and December 2007—when the relative price of food staples rose by an average of 5.6%—to find that the number of individuals living under the extreme poverty line increased by 155 million, with almost three‐quarters of this increase taking place in East Asia. To take the second‐order effects into account, the paper links household survey data with a global general equilibrium model, finding that the same increase in consumer prices of agricultural goods (modeled by increasing demand for first‐generation biofuels) would raise the number of individuals living under extreme poverty by 32 million, with nearly the entire increase occurring in South Asia and Sub‐Saharan Africa.     

Oil price shocks and stock market activities: Evidence from oil-importing and oil-exporting countries

While the relationship between oil prices and stock markets is of great interest to economists, previous studies do not differentiate oil-exporting countries from oil-importing countries when they investigate the effects of oil price shocks on stock market returns. In this paper, we address this limitation using a structural VAR analysis. Our main findings can be summarized as follows: First, the magnitude, duration, and even direction of response by stock market in a country to oil price shocks highly depend on whether the country is a net importer or exporter in the world oil market, and whether changes in oil price are driven by supply or aggregate demand. Second, the relative contribution of each type of oil price shocks depends on the level of importance of oil to national economy, as well as the net position in oil market and the driving forces of oil price changes. Third, the effects of aggregate demand uncertainty on stock markets in oil-exporting countries are much stronger and more persistent than in oil-importing countries. Finally, positive aggregate and precautionary demand shocks are shown to result in a higher degree of co-movement among the stock markets in oil-exporting countries, but not among those in oil-importing countries.