An empirical test of purchasing power parity in selected developing countries: a panel data approach

Abstract

This paper examines the empirical validity of Purchasing Power Parity (PPP) for certain large developing economies by using a panel unit root methodology. The test results show that a long run real exchange rate depreciation trend exists in certain developing countries. Without considering this depreciation trend, it is hard to verify the stationarity and to explain the existence of the extremely long half-lives of the real exchange rates. When a linear time trend is included in the tests, the results tend to support the stationarity of the underlying real exchange rate processes, and the half-lives are significantly shorter and their range can be explained by transitory disturbances.     

Price convergence in US cities: a cointegration approach with two structural breaks

This article investigates how the price indices of major cities of the US respond to the shock from a city and from monetary policy. We find that the crisis of Bretton Woods system in 1968 and the oil crisis in 1974 should be incorporated as structural breaks in monetary policy variables and price indices. Using cointegration technique with structural break in our aggregated data, we find that the average half-life is 1.75 years, which is closer to what some of others found in disaggregated data, and that the interest rate is an effective tool for controlling cities’ price in short run.     

Real Exchange Rate Dynamics in the Asian Economies: Can Regime Shifts Explain Purchasing Power Parity Puzzles?

Abstract

We show that the strong version of the purchasing power parity (PPP) hypothesis holds in most of the US dollar real exchange rates using cointegration method that accounts for breaks in the models. The break dates in seven of the Asian currencies coincide with the two rounds of currency depreciation recorded during the 1997–1998 financial crises. We obtain a mean half-life estimate of about 10 months for PPP to converge to its long-run equilibrium level. Our confidence intervals based on persistence profile approach for the half-lives is much narrower than previous evidence might indicate. Taken together, these results show that mean reversion is stronger than commonly thought.     

Estimating the Half-life of Advertisements

The effectiveness of an advertisement wears out over time; eventually, it becomes totally ineffective. The author proposes a concept for measuring the lifetime of an advertisement and derives closed-form expressions for it under certain conditions. In addition, the author distinguishes the proposed concept, the half-life of an advertisement, from the prevalent notion of the duration of advertising effects. More importantly, the information on the half-life of ads is actionable from a managerial standpoint, whereas that on the duration of advertising effect is hypothetical. To enable advertisers to estimate the half-life of their ads, the author describes an estimation approach and illustrates its use by applying it to the advertising of the Dockers® brand of Levi Strauss and Company. Substantively, the lifetime of advertisements for the Dockers® brand is about three months. Thus, advertisers are well-advised to periodically estimate the half-life of their ads, so that they can plan the timing to replace worn out advertisements.     

空、实仓压力半衰期关系的探讨

通过对影响半衰期的各个因素的分析,提出空、实仓半衰期的数学关系。已知空仓半衰期、粮食品种通过表格或曲线可以查出某装粮高度的理论实仓半衰期。通过修正系数修正就可以得出近似实仓半衰期。     

Credit card debt and consumption: evidence from household-level data

This research investigates the relationship between credit card debt and consumption using household level data. This is a departure from the previous studies which have used aggregate measures of consumption and general debt such as the Debt Service Ratio or total revolving credit. We use a detailed monthly survey of credit card use to impute credit card debt to respondents from the Consumer Expenditure Survey sample. In contrast to some earlier studies using aggregate data, we find a negative relationship between debt and consumption growth. Our work shows that a $1000 increase in credit card debt results in a decrease in quarterly consumption growth of almost 2%. Investigations are also made into effects of debt within different age categories and into the impact of expected income growth on the debt–consumption relationship.     

Mean-reversion in closed-end fund discount: evidence from half-life

This article examines the mean-reversion properties of the discount on UK and US closed-end funds. While the discounts are tested I(1), strong statistical evidence of mean-reversion is ascertained by bias-corrected bootstrap half-life estimates. The estimates also indicate that equity-based funds converge to the steady-state level faster than fixed income funds. In addition, although an equilibrium pricing condition postulates an inverse relation between half-life and the discount size, correlation estimates fail to show strong support for the relation.     

A censored system of cigarette and alcohol consumption

Many previous studies of US cigarette and alcohol consumption have focused on single equations. However, the addictive nature of consumption suggests that it is more appropriate to model these products as a system. We propose a two-step estimation procedure and apply the procedure to a system of equations for cigarette, beer and wine consumption. Results differ from those derived from an existing two-step procedure. Findings suggest that consumption of cigarettes, beer and wine is responsive to income changes but the elasticities are rather small. Personal physiques, education, age, race, ethnicity, health, gender, employment status, and regions also play significant roles in consumption.     

Are real exchanges rate series really persistent?: evidence from three commonwealth of independent states countries

This article sets out to examine the degree of persistence in the real exchange rates of Kazakhstan, Kyrgyzstan and Russia, and tests the validity of Purchasing power parity (PPP) using monthly data covering 1995:01–2013:12 period. The sum of autoregressive (AR) coefficients is used in order to examine persistence of the real exchange rate series and grid-bootstrap method is employed for the confidence intervals. The tests performed suggest two results: (1) Covering the full sample and sub-sample periods, excluding Kyrgyzstan in 1995:01–1998:07 and Russia in 2008:09–2013:12 periods, disregarding the structural breaks in the data generating process, there is high persistency in real exchange rates; (2) there is evidence in support of PPP covering the full sample for every country except for Kyrgyzstan in 1995:01–1998:07 and Russia in 2008:09–2013:12 periods.     

Cost-utility analysis of life-long prophylaxis with recombinant factor VIIIFc vs recombinant factor VIII for the management of severe hemophilia A in Sweden

Aims: Prophylaxis with recombinant factor VIII (rFVIII) is the standard of care for severe hemophilia A in Sweden. The need for frequent injections with existing rFVIII products may, however, result in poor adherence to prophylaxis, leading to increased bleeding and long-term joint damage. Recombinant FVIIIFc (rFVIIIFc) is an extended half-life fusion protein which can offer prolonged protection and reduced dosing frequency. The objective of this study was to evaluate the cost-utility of prophylaxis with rFVIIIFc in severe hemophilia A from the perspective of the Swedish health system.

Methods: A Markov model was built to estimate lifetime costs and benefits of prophylaxis with rFVIIIFc vs rFVIII products. Clinical outcomes were represented by annualized bleeding rate (ABR) and quality of life via disutility applied to bleeding events and injection frequency. Costs included the cost of FVIII for routine prophylaxis and bleed resolution. The pooled comparator was costed by weighting the cost of individual products by their market share.

Results: In the base case, rFVIIIFc was dominant vs the pooled comparator. Savings of SEK 9.0 million per patient resulted from lower factor consumption for prophylaxis and bleed resolution. Fewer bleeds and reduced injection frequency yielded an estimated 0.59 quality-adjusted life years (QALYs). Results were sensitive to drug dosage and robust to variation in other parameters. Probabilistic sensitivity analysis suggested a greater than 85% probability of rFVIIIFc being cost-effective at a willingness-to-pay threshold of 500,000 SEK/QALY.

Limitations: Due to unavailibilty of patient-level data, treatment benefit was based on a non-adjusted indirect comparison. Dosing and treatment outcomes were assumed to persist over the model duration in the absence of long-term outcome data.

Conclusion: The results suggest that rFVIIIFc may be a cost-effective option for hemophilia A prophylaxis, generating greater quality of life and reduced costs for the Swedish payer compared to more frequently administered rFVIII alternatives.