The univariate statistical properties of agricultural price series need to be examined as a first step in the analysis of price transmission mechanisms. However, in the case of weekly price series, increasingly available, the testing procedures usually applied in this step are not suitable to deal with evolving seasonal effects. In this study, a method of testing for seasonal unit roots in weekly series of agricultural prices is described. When the deterministic seasonal component does not remain constant over time, the restricted evolving spline model (RESM) is shown to be a useful parametric formulation to capture the deterministic seasonal pattern. Therefore, the RESM model should be included as a deterministic component in auxiliary regression for unit root tests at seasonal frequencies. This proposal is applied to three weekly series of Canary Islands banana prices. From the standard seasonal unit root tests, the null hypothesis is failed to be rejected at the 5% or 10% significance level at some seasonal frequencies for each one of the series. Once critical values are obtained by simulation exercises when the RESM model is included, the hypotheses of unit root are rejected at each one of the seasonal frequencies for all of the three series. 相似文献
In this paper, we examine irreversible investment decisions in duopoly games with a variable economic climate. Integrating timing flexibility, competition, and changes in the economic environment in the form of a cash flow process with regime switching, the problem is formulated as a stopping‐time game under Stackelberg leader‐follower competition, in which both players determine their respective optimal market entry time. By extending the variational inequality approach, we solve for the free boundaries and obtain optimal investment strategies for each player. Despite the lack of regularity in the leader's obstacle and the cash flow regime uncertainty, the regime‐dependent optimal policies for both the leader and the follower are obtained. In addition, we perform comprehensive numerical experiments to demonstrate the properties of solutions and to gain insights into the implications of regime switching. 相似文献
The financialization of housing has been increasingly identified as an important driver of social and economic change in contemporary capitalism. Focusing on the Brazilian context, this article considers the extent to which recent changes in housing regulations, policies and markets confirm or challenge narratives about the financialization of housing in the international academic debate. I argue that while many of the trends stressed in the literature are apparent, more extreme processes of financialization within the Brazilian housing sector remain limited––not only because of institutional and regulatory constraints, path dependence or political resistance, but also because of fundamental structural conditions of Brazil's position as a peripheral economy. Three different but mutually reinforcing processes are scrutinized in order to evaluate the financialization of housing and its limits in Brazil: the re‐regulation of the real estate financial sector initiated in the 1990s; the changing funding patterns among real estate companies since the mid‐2000s; and the increasing commodification of housing induced by a large‐scale and heavily subsidized housing program launched in 2009. 相似文献
This paper examines the causal relationship between the housing prices (HP) and the international capital flows (ICF) in China. With structural changes existing, we find that long-run relationship using full-sample data is unstable, suggesting that traditional Granger causality test is not reliable. However, we further find an unstable short-run relationship between ICF and HP when assessing the stability of the parameters and there are bidirectional causal relationships between ICF and HP for several sub-periods. Additionally, our findings indicate both positive and negative bidirectional causal relations between the series. Based on the arbitrage of ICF, the results suggest that the rise of Chinese HP is the underlying force for the inflows of international capital. Meanwhile, a surge in capital inflows may be accompanied by a rise in the price of housing. This confirms the theoretical analysis that there is an interconnected transmission mechanism between the ICF and the HP, which is diverse and depends both on the flow of ICF and on other factors. 相似文献
One way to ensure food safety is by enhancing compliance at the farm level. This study investigates the status, estimates the cost, identifies the determinants, and assesses the impact of compliance with food safety measures (FSM) in milk production in Nepal. The study is based on primary data collected from six high milk producing districts that captures the geographical and institutional diversity of milk production. Results show that the status of farm level compliance with FSM is not very encouraging. Also, the intensity of adoption of FSM exhibits significant inter- and intra-district variations. It varies positively with herd size but the additional cost of compliance with FSM varies negatively with herd size. Among other determinants, access to information, and incidence of inspection for conformity with safety and quality standards are also associated with higher adoption of FSM. Finally, we also estimate the impact of FSM on farm-gate prices and farmers’ profits and conduct several robustness checks. 相似文献
Background: Non-vitamin K antagonist oral anticoagulants (NOACs) have been included in international guidelines as important alternatives to vitamin K antagonists (VKAs) for the treatment of venous thromboembolism (VTE) and stroke prevention in non-valvular atrial fibrillation (NVAF). Meanwhile, in the Netherlands, NOACs are widely used next to VKAs. The objective of this study is to estimate the cost-effectiveness of treatment with rivaroxaban compared to VKAs in NVAF and VTE patients in the Netherlands, using data from international prospective observational phase IV studies.
Methods: Two models were developed to represent NVAF and VTE patients, populated with patients from the XANTUS (NCT01606995) and XALIA (NCT01619007) international prospective observational studies. The 1-year cost-effectiveness of rivaroxaban use, compared to VKAs, was explored in a population consisting of NVAF and VTE patients (base case) as well as for four scenarios with sub-populations: NVAF patients only, VTE patients only, NVAF patients with unstable international normalized ratio (INR), and NVAF patients using an INR self-measuring device.
Results: In the base case, rivaroxaban saved €72,350 and gained 21 quality-adjusted life-years (QALYs) in a simulation of 2,000 patients over the use of VKAs. Ergo, rivaroxaban was dominant over VKAs. The probabilistic sensitivity analysis showed a probability of 85% for rivaroxaban being dominant and 100% at a willingness-to-pay threshold of €20,000/QALY. Rivaroxaban appeared to be dominant in all scenarios as well, except for the NVAF-patients-only scenario where the incremental cost-effectiveness ratio (ICER) was €157/QALY.
Conclusions: In patients with NVAF or VTE, rivaroxaban treatment is likely to be cost-effective and a potentially cost-saving alternative to VKA in the Netherlands. 相似文献
Commodity price shocks are an important type of external shock and are often cited as a problem for economic growth in Sub‐Saharan Africa. We choose nine Sub‐Saharan African countries that are heavily dependent on a single agricultural commodity for a significant portion of their income. This paper quantifies the impact of agricultural commodity price shocks using a structural non‐linear dynamic model. The novel aspect of this study is that we determine whether the response of per capita GDP for the selected Sub‐Saharan African countries is different to unexpected increases in agricultural commodity prices as opposed to decreases in prices. We conclude that there is very little evidence that an unanticipated price increase (decrease) will lead to a significantly different response in per capita incomes. 相似文献