Short Sampling Period Research Articles

Improving Business Cycle Forecasts' Accuracy - What Can We Learn from Past Errors?

This paper addresses the question whether forecasters could have been able to produce better forecasts by using the available information more efficiently (informational efficiency of forecast). It is tested whether forecast errors covariate with indicators such as survey results, monetary data, business cycle indicators, or financial data. Because of the short sampling period and data problems, a non parametric ranked sign test is applied. The analysis is carried out for GDP and its main components. The study differentiates between two types of errors: Type I error occurs when forecasters neglect the information provided by an indicator. As type II error a situation is labelled in which forecasters have given too much weight to an indicator. In a number of cases forecast errors and the indicators are correlated, though mostly at a rather low level of significance. In most cases type I errors have been found. Additional tests reveal that there is little evidence of institution specific as well as forecast horizon specific effects. In many cases, co-variations found for GDP are not refected in one of the expenditure side components et vice versa.

Long-term time-lapse video provides near complete records of floral visitation

Accurate records of floral visitors are critical for understanding plant pollinator interactions. However, to date, sampling methods are constrained to short sampling periods and may be subject to observer interference. Thus, complete records without sampling bias are rare. We use a portable time-lapse digital video camera to capture near-complete records of visitors to flowers over their entire blooming period. We show the broad applicability of this method by filming a wide variety of flowers of different shapes and inflorescence types. We test the importance of long-term records by studying visitors to Cornus canadensis (bunchberry dogwood). Visitors to C. canadensis filmed simultaneously at four different sites show variation (both in rates and taxa) between inflorescences, between sites, throughout the day, and throughout the season. For C. canadensis our films also provide a record of pollen placement (an indirect measure of male fitness) and fruit set (female fitness). This technique provides near complete records of floral visitors, is likely to capture rare events, and allows simultaneous long-term filming. These results emphasize the importance of both long-term data collection and simultaneous recording at multiple sites for pollination studies.

Sources of Variation in a Two-Step Monitoring Protocol for Species Clustered in Conspicuous Points: Dolichotis patagonum as a Case Study.

In species showing distributions attached to particular features of the landscape or conspicuous signs, counts are commonly made by making focal observations where animals concentrate. However, to obtain density estimates for a given area, independent searching for signs and occupancy rates of suitable sites is needed. In both cases, it is important to estimate detection probability and other possible sources of variation to avoid confounding effects on measurements of abundance variation. Our objective was to assess possible bias and sources of variation in a two-step protocol in which random designs were applied to search for signs while continuously recording video cameras were used to perform abundance counts where animals are concentrated, using mara (Dolichotis patagonum) as a case study. The protocol was successfully applied to maras within the Península Valdés protected area, given that the protocol was logistically suitable, allowed warrens to be found, the associated adults to be counted, and the detection probability to be estimated. Variability was documented in both components of the two-step protocol. These sources of variation should be taken into account when applying this protocol. Warren detectability was approximately 80% with little variation. Factors related to false positive detection were more important than imperfect detection. The detectability for individuals was approximately 90% using the entire day of observations. The shortest sampling period with a similar detection capacity than a day was approximately 10 hours, and during this period, the visiting dynamic did not show trends. For individual mara, the detection capacity of the camera was not significantly different from the observer during fieldwork. The presence of the camera did not affect the visiting behavior of adults to the warren. Application of this protocol will allow monitoring of the near-threatened mara providing a minimum local population size and a baseline for measuring long-term trends.

Inflation, deflation, and uncertainty: What drives euro-area option-implied inflation expectations, and are they still anchored in the sovereign debt crisis?

We tackle two questions in this paper: In the sovereign debt crisis, what moves the euro-area inflation outlook, and has the firm anchoring of medium to long-term inflation expectations been affected? We try to answer these questions by looking at option-implied probability density functions of future inflation. Deriving densities from a new data set on options on the euro-area harmonised index of consumer prices (excluding tobacco) provides us with the full distribution of inflation expectations, including uncertainty and asymmetry of market participants' beliefs about the inflation outlook. The daily data set allows us to analyse the effects of monetary policy announcements and macro news in a time-varying event study framework despite the short sample period from 2009 to 2013. Due to renewed fears of deflation, we compare option-implied and statistical density functions to gain insight into deflation risk. Inflation expectations show a decreasing mean but growing uncertainty, especially since the intensification of the sovereign debt crisis in mid-2011. Around the same time, the influence of monetary policy announcements on inflation expectations across all horizons diminished. Tail events such as deflation, although still contained, have become more probable. The impact of macroeconomic news on inflation probabilities has overall decreased and shifted towards countries more affected by the crisis. This paper's results regarding the anchoring of inflation expectations are twofold: The mean and low sensitivity to actual news speak for anchored inflation expectations, whereas the growing uncertainty reveals market participants' concerns about possible extreme inflation or deflation outcomes in the future.

How integrated are behavioral and endocrine stress response traits? A repeated measures approach to testing the stress-coping style model.

It is widely expected that physiological and behavioral stress responses will be integrated within divergent stress-coping styles (SCS) and that these may represent opposite ends of a continuously varying reactive–proactive axis. If such a model is valid, then stress response traits should be repeatable and physiological and behavioral responses should also change in an integrated manner along a major axis of among-individual variation. While there is some evidence of association between endocrine and behavioral stress response traits, few studies incorporate repeated observations of both. To test this model, we use a multivariate, repeated measures approach in a captive-bred population of Xiphophorus birchmanni. We quantify among-individual variation in behavioral stress response to an open field trial (OFT) with simulated predator attack (SPA) and measure waterborne steroid hormone levels (cortisol, 11-ketotestosterone) before and after exposure. Under the mild stress stimulus (OFT), (multivariate) behavioral variation among individuals was consistent with a strong axis of personality (shy–bold) or coping style (reactive–proactive) variation. However, behavioral responses to a moderate stressor (SPA) were less repeatable, and robust statistical support for repeatable endocrine state over the full sampling period was limited to 11-ketotestosterone. Although post hoc analysis suggested cortisol expression was repeatable over short time periods, qualitative relationships between behavior and glucocorticoid levels were counter to our a priori expectations. Thus, while our results clearly show among-individual differences in behavioral and endocrine traits associated with stress response, the correlation structure between these is not consistent with a simple proactive–reactive axis of integrated stress-coping style. Additionally, the low repeatability of cortisol suggests caution is warranted if single observations (or indeed repeat measures over short sampling periods) of glucocorticoid traits are used in ecological or evolutionary studies focussed at the individual level.

Effects of health information technology on malpractice insurance premiums.

ObjectivesThe widespread adoption of health information technology (IT) will help contain health care costs by decreasing inefficiencies in healthcare delivery. Theoretically, health IT could lower hospitals' malpractice insurance premiums (MIPs) and improve the quality of care by reducing the number and size of malpractice. This study examines the relationship between health IT investment and MIP using California hospital data from 2006 to 2007.MethodsTo examine the effect of hospital IT on malpractice insurance expense, a generalized estimating equation (GEE) was employed.ResultsIt was found that health IT investment was not negatively associated with MIP. Health IT was reported to reduce medical error and improve efficiency. Thus, it may reduce malpractice claims from patients, which will reduce malpractice insurance expenses for hospitals. However, health IT adoption could lead to increases in MIPs. For example, we expect increases in MIPs of about 1.2% and 1.5%, respectively, when health IT and labor increase by 10%.ConclusionsThis study examined the effect of health IT investment on MIPs controlling other hospital and market, and volume characteristics. Against our expectation, we found that health IT investment was not negatively associated with MIP. There may be some possible reasons that the real effect of health IT on MIPs was not observed; barriers including communication problems among health ITs, shorter sample period, lower IT investment, and lack of a quality of care measure as a moderating variable.

A burning desire for smoke? Sampling insects favoured by forest fire in the absence of fire

Fire-favoured insects are difficult to sample except opportunistically after forest fires. Here, we tested if smoke from a small fire could be an efficient way to sample such insects. Insects were sampled over ca. 10 h hours, by hand-picking and netting on screens put up around the fire. Two specimens of the rare and redlisted Hormopeza spp. (Diptera, Empididae) were caught. Large numbers (>20,000) of Microsania spp. (Diptera, Platypezidae) were caught, but none in the absence of smoke. The numbers of Microsania spp. clearly peaked in late afternoon, and a short sampling period would be sufficient if targeting only this taxon. Of the almost 200 species of Coleoptera, 17 % were considered as fire-favoured, contributing 9 % of the specimens, suggesting low efficiency of the method for this group. Using 23 sites differing in fire history, catches of Microsania spp. were unaffected by numbers and area of forest fire (preceding 5 years and within 10 km radius over the sampling sites). In contrast, there was a weak trend for the proportion of fire-favoured Coleoptera to increase with increasing number of fires. To conclude, smoke as produced in our study can clearly attract fire-favoured Diptera, but smoke had only a weak effect on fire-favoured Coleoptera in the study area. It is still likely that selectively picking specimens of species attracted to smoke is a more cost-efficient method than using, e.g., Malaise traps that catch indiscriminately.

High-order moments and extreme value approach for value-at-risk

Abstract We modify a two-step approach by McNeil and Frey (2000) for forecasting Value-at-Risk (VaR). Our approach combines the asymmetric GARCH (GJR) model that allows the high-order moments (i.e., skewness and kurtosis) of the skewed generalized t (SGT) distribution to rely on the past information set to estimate volatility, and the modified Hill estimator (Huisman et al., 2001) for estimating the innovation distribution tail of the GJR model. Using back-testing of the daily return series of 10 stock markets, the empirical results show that our proposed approach could give better one-day VaR forecasts than McNeil and Frey (2000) and the GJR/GARCH models with alternative distributions. In addition, our proposed approach also provides the accuracy of expected shortfall estimates. The evidence demonstrates that our proposed two-step approach that incorporates the modified Hill estimator into the GJR model based on the SGT density with autoregressive conditional skewness and kurtosis provides consistently accurate VaR forecasts in the short and longer sample periods.

Recommended survey designs for occupancy modelling using motion-activated cameras: insights from empirical wildlife data.

Motion-activated cameras are a versatile tool that wildlife biologists can use for sampling wild animal populations to estimate species occurrence. Occupancy modelling provides a flexible framework for the analysis of these data; explicitly recognizing that given a species occupies an area the probability of detecting it is often less than one. Despite the number of studies using camera data in an occupancy framework, there is only limited guidance from the scientific literature about survey design trade-offs when using motion-activated cameras. A fuller understanding of these trade-offs will allow researchers to maximise available resources and determine whether the objectives of a monitoring program or research study are achievable. We use an empirical dataset collected from 40 cameras deployed across 160 km2 of the Western Slope of Colorado, USA to explore how survey effort (number of cameras deployed and the length of sampling period) affects the accuracy and precision (i.e., error) of the occupancy estimate for ten mammal and three virtual species. We do this using a simulation approach where species occupancy and detection parameters were informed by empirical data from motion-activated cameras. A total of 54 survey designs were considered by varying combinations of sites (10–120 cameras) and occasions (20–120 survey days). Our findings demonstrate that increasing total sampling effort generally decreases error associated with the occupancy estimate, but changing the number of sites or sampling duration can have very different results, depending on whether a species is spatially common or rare (occupancy = ψ) and easy or hard to detect when available (detection probability = p). For rare species with a low probability of detection (i.e., raccoon and spotted skunk) the required survey effort includes maximizing the number of sites and the number of survey days, often to a level that may be logistically unrealistic for many studies. For common species with low detection (i.e., bobcat and coyote) the most efficient sampling approach was to increase the number of occasions (survey days). However, for common species that are moderately detectable (i.e., cottontail rabbit and mule deer), occupancy could reliably be estimated with comparatively low numbers of cameras over a short sampling period. We provide general guidelines for reliably estimating occupancy across a range of terrestrial species (rare to common: ψ = 0.175–0.970, and low to moderate detectability: p = 0.003–0.200) using motion-activated cameras. Wildlife researchers/managers with limited knowledge of the relative abundance and likelihood of detection of a particular species can apply these guidelines regardless of location. We emphasize the importance of prior biological knowledge, defined objectives and detailed planning (e.g., simulating different study-design scenarios) for designing effective monitoring programs and research studies.

Control of a Group of Mobile Robots Based on Formation Abstraction and Decentralized Locational Optimization

In this paper, we propose a new method of controlling a group of mobile robots based on formation abstraction. The shape of a formation is represented by a deformable polygon, which is constructed by bending a rectangle, to go through narrow spaces without colliding with obstacles. If the trajectory of the front end point, as well as the width and the length of the formation, are given, the formation automatically reshapes itself to fit the area through which the front part of the group has already safely passed. Furthermore, the robots continuously try to optimize their positions to decrease the risk of collisions by integrating a decentralized locational optimization algorithm into the formation control. We show that the objective function, taking into account the distance between robots, does not decrease for fixed and nonconvex polygonal formation shapes if the zero-order hold control is applied for a sufficiently short sampling period. We also analyze the influence of the decentralized locational optimization algorithm on the objective function in the case of variable formations. The effectiveness of the proposed method is demonstrated in both simulations and real robot experiments.

Optimal Digital Controller Design for a Servo Motor Taking Account of Intersample Behavior

SUMMARYA continuous‐time plant with a discretized continuous‐time controller does not yield stability if the sampling rate is lower than some certain level. Thus far, high‐performance electronic control has made use of expensive hardware needed to implement discretized continuous‐time controllers; low‐cost hardware generally does not have a sufficiently high sampling rate. This technical note presents results comparing performance indexes with and without intersample behavior, and provides some answers to the question of how a low‐specification device can control a plant effectively. We consider a machine simulating wafer handling robots, which is an electromechanical system driven by a direct drive motor, at a semiconductor factory. We illustrate the controller design for the robot with and without intersample behavior, and present simulations and experimental results using these controllers. Taking intersample behavior into account proves to be effective in improving control performance and makes it possible to choose a relatively long sampling period. Controller design in terms of the performance index with intersample behavior makes it possible to deal with situations in which a sufficiently short sampling period may not be employed, and freedom of controller design may be widened, especially regarding the choice of the sampling period.

Do return and volatility traverse the Middle Eastern and North African (MENA) stock markets borders?

Purpose – This paper aims to examine the dynamic relationship across stock market returns in Morocco, Tunisia, Egypt, Lebanon, Jordan, Kuwait, Bahrain, Qatar, United Arabic Emirates (UAE), Saudi Arabia, and Oman from June 2005 to January 2012. Design/methodology/approach – The paper uses a multivariate model with leptokurtic distribution which allows for both return asymmetry and fat tails. The paper also derives from the model the conditional correlation between stock markets and examines the impact of the global financial crisis of 2008 on the conditional variance and correlation. Findings – The empirical results show that the Middle East and North African (MENA) markets are interconnected by their volatilities and not by their returns. Volatility persists in each market and significant volatility spillovers from small to relatively larger markets. During the crisis, the paper finds that conditional volatilities across markets increase but then during the post-crisis period return to their pre-crisis levels. More importantly, the conditional correlation behaves differently, with a significant evidence of downwards trend in some correlations across the MENA stock markets. Research limitations/implications – One limitation of the study relates to the relatively short-sample period which drives the empirical results. Practical implications – The key results imply that there is still a possibility of benefits from portfolio diversification across specific MENA countries during periods of high volatility. Originality/value – No previous study investigates the transmission of both the first and second moments of the return series across the MENA stock markets allowing for time-varying volatility and correlation and accounts for the 2008 global financial crisis to examine whether the conditional volatilities and correlations have strengthened or weakened during the crisis and afterwards.

Information and Communications Technology (ICT) and Trade in Emerging Market Economies

This paper examines the effects of information and communications technology (ICT) on international trade in emerging markets. Using panel data for 40 emerging market economies (EMEs) for a period from 1995 to 2010, we estimate fixed effects models of exports and imports on ICT and other control variables. Our ICT variables include the growth of telecom investment, international Internet bandwidth, Internet subscriptions per 100 people, and the number of Internet hosts per 100 people. We use the share of total exports and of total imports in GDP as the dependent variables. Additionally, we consider the GDP share of exports and imports for goods and services separately. The main control variables are: per capita GDP growth, population growth, and the GDP growth for the rest of the world. The empirical results overwhelmingly suggest that Internet bandwidth, Internet subscriptions, and Internet hosts have significant positive impacts on export share while all four ICT variables including telecom investment growth have significant positive impacts on import shares in emerging market economies. This result is robust across shorter sample period, a subsample of EMEs, alternative estimation method, and alternative model specifications. There are important policy implications of this result for developing countries.

Collection Efficiencies of High Flow Rate Personal Respirable Samplers When Measuring Arizona Road Dust and Analysis of Quartz by X-ray Diffraction

Prolonged exposure to respirable crystalline silica (RCS) causes silicosis and is also considered a cause of cancer. To meet emerging needs for precise measurements of RCS, from shorter sampling periods (<4h) and lower air concentrations, collaborative work was done to assess the differences between personal respirable samplers at higher flow rates. The performance of FSP10, GK2.69, and CIP 10 R samplers were compared with that of the Safety In Mines Personal Dust Sampler (SIMPEDS) sampler as a reference, which is commonly used in the UK for the measurement of RCS. In addition, the performance of the FSP10 and GK 2.69 samplers were compared; at the nominal flow rates recommended by the manufacturers of 10 and 4.2 l · min−1 and with flow rates proposed by the National Institute for Occupational Safety and Health of 11.2 and 4.4 l · min−1. Samplers were exposed to aerosols of ultrafine and medium grades of Arizona road dust (ARD) generated in a calm air chamber. All analyses for RCS in this study were performed at the Health and Safety Laboratory. The difference in flow rates for the GK2.69 is small and does not result in a substantial difference in collection efficiency for the dusts tested, while the performance of the FSP10 at 11.2 l · min−1 was more comparable with samples from the SIMPEDS. Conversely, the GK2.69 collected proportionately more crystalline silica in the respirable dust than other samplers, which then produced RCS results most comparable with the SIMPEDS. The CIP 10 R collected less ultrafine ARD than other samplers, as might be expected based on earlier performance evaluations. The higher flow rate for the FSP10 should be an added advantage for task-specific sampling or when measuring air concentrations less than current occupational exposure limits.

Inflation, Deflation, and Uncertainty: What Drives Euro Area Option-Implied Inflation Expectations and are They Still Anchored in the Sovereign Debt Crisis?

We tackle two questions in this paper: In the sovereign debt crisis, what moves the euro area inflation outlook and has the firm anchoring of medium to long-term inflation expectations been touched? Deriving densities from a new data set on options on the euro area harmonized index of consumer prices provides us with the full distribution of inflation expectations. The daily data set allows us to analyze effects of monetary policy announcements and macro news in a time varying event study framework despite the short sample period from 2009 to 2013. Due to renewed fears of deflation we compare option-implied and statistical density functions to gain insight into deflation risk. Inflation expectations show a decreasing mean but growing uncertainty especially since the intensification of the sovereign debt crisis in mid-2011. Around the same time the influence of monetary policy announcements on inflation expectations diminished. Tail events such as deflation although still contained became more probable. The impact of macroeconomic news to explain inflation probabilities overall decreased and shifted towards countries more affected by the crisis. Concerning the anchoring of inflation expectations the paper provides a twofold result: The mean and low sensitivity to actual news speak for anchored inflation expectations whereas the growing uncertainty reveals market participants concerns about possible extreme inflation or deflation outcomes in the future.

Non-Constant Prediction-Step MPC for Processes with Multi-Scale Dynamics

Motivated by applications in minerals processing, a novel model predictive control scheme is presented with non-constant prediction step size. In the proposed scheme, the sampling rate of the prediction and control horizons changes, with nearer steps having a shorter sampling period than ones in the more distant future. This approach allows for fine tuning of the control trajectory over the near horizon, whilst still allowing for long prediction and control horizons to account for slow dynamics. This may find application in many chemical and minerals processing plants where process units have multiple time-scale dynamics. Extensions to decentralized control of process networks are presented. The approach is illustrated using an industrial case study.

Economic threshold for Tetranychus urticae (Acari: Tetranychidae) in clementine mandarins Citrus clementina

Tetranychus urticae is a key pest of citrus in Spain, especially of clementine mandarin trees. The effects of this mite on fruit production were assessed in 24 clementine trees for three consecutive years. Trees were visited weekly and spider mite and phytoseiid mite populations and leaf flush patterns were estimated. At the end of the season, mandarins were harvested, weighed, and mite damage (scarring on the fruit) characterized. Negative relationships between spider mite density and yield (kg/tree) and fruit damage (% scarred fruit rind) were found. The multivariate regressions highlighted the key role of phytoseiid mites and leaf flush patterns, which were negatively related to fruit damage. The shortest sampling period that satisfactorily predicted fruit damage at harvest, extended from August to mid-October. For IPM purposes, an action threshold of 31.1 mites m⁻² of symptomatic leaf was estimated. Taking into account spider mite dynamics, the economic threshold ranged from 10 to 15 mites m⁻² of symptomatic leaf. When this threshold is exceeded growers would have a 1-week window to apply the control technologies against T. urticae of their choice.

A coupled sensor-spectrophotometric device for continuous measurement of formaldehyde in indoor environments

Despite long-standing awareness of adverse health effects associated with chronic human exposure to formaldehyde, this hazardous air pollutant remains a challenge to measure in indoor environments. Traditional analytical techniques evaluate formaldehyde concentrations over several hours to several days in a single location in a residence, making it difficult to characterize daily temporal and spatial variation in human exposure to formaldehyde. There is a need for portable, easy-to-use devices that are specific and sensitive to gas-phase formaldehyde over short sampling periods so that dynamic processes governing formaldehyde fate, transport, and potential remediation in indoor environments may be studied more effectively. A recently developed device couples a chemical sensor element with spectrophotometric analysis for detection and quantification of part per billion (ppbv) gas-phase formaldehyde concentrations. This study established the ability of the coupled sensor-spectrophotometric device (CSSD) to report formaldehyde concentrations accurately and continuously on a 30-min sampling cycle at low ppbv concentrations previously untested for this device in a laboratory setting. Determination of the method detection limit (MDL), based on 40 samples each at test concentrations of 5 and 10 ppbv, was found to be 1.9 and 2.0 ppbv, respectively. Performance of the CSSD was compared with the dinitrophenylhydrazine (DNPH) derivatization method for formaldehyde concentrations ranging from 5-50 ppbv, and a linear relationship with a coefficient of determination of 0.983 was found between these two analytical techniques. The CSSD was also used to monitor indoor formaldehyde concentrations in two manufactured homes. During this time, formaldehyde concentrations varied from below detection limit to 65 ppbv and were above the US National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL) of 16 ppbv, which is also the exposure limit value now adopted by the US Federal Emergency Management Agency (FEMA) to procure manufactured housing, 80% and 100% of the time, respectively.

Evaluation of the measurement uncertainty in automated long-term sampling of PCDD/PCDFs

Since the publication of the first version of European standard EN-1948 in 1996, long-term sampling equipment has been improved to a high standard for the sampling and analysis of polychlorodibenzo-p-dioxin (PCDD)/polychlorodibenzofuran (PCDF) emissions from industrial sources. The current automated PCDD/PCDF sampling systems enable to extend the measurement time from 6-8 h to 15-30 days in order to have data values better representative of the real pollutant emission of the plant in the long period. EN-1948:2006 is still the European technical reference standard for the determination of PCDD/PCDF from stationary source emissions. In this paper, a methodology to estimate the measurement uncertainty of long-term automated sampling is presented. The methodology has been tested on a set of high concentration sampling data resulting from a specific experience; it is proposed with the intent that it is to be applied on further similar studies and generalized. A comparison between short-term sampling data resulting from manual and automated parallel measurements has been considered also in order to verify the feasibility and usefulness of automated systems and to establish correlations between results of the two methods to use a manual method for calibration of automatic long-term one. The uncertainty components of the manual method are analyzed, following the requirements of EN-1948-3:2006, allowing to have a preliminary evaluation of the corresponding uncertainty components of the automated system. Then, a comparison between experimental data coming from parallel sampling campaigns carried out in short- and long-term sampling periods is realized. Long-term sampling is more reliable to monitor PCDD/PCDF emissions than occasional short-term sampling. Automated sampling systems can assure very useful emission data both in short and long sampling periods. Despite this, due to the different application of the long-term sampling systems, the automated results could not be directly compared with manual results, not even in terms of measurement uncertainty. This investigation focuses on both uncertainty and repeatability of the automated sampling method. The standard 20988, developed by Internarional Organization of Standardization (ISO) can be used to estimate the measurement uncertainty. The results confirm that the uncertainties of manual and automated methods are comparable. At the same time, it is not appropriate to consider the manual method as a reference for the evaluation of the uncertainty of the automated sampling system, due to the high variability of both systems.

Pricing variance and volatility swaps in a stochastic volatility model with regime switching: discrete observations case

This study presents a set of closed-form exact solutions for pricing discretely sampled variance swaps and volatility swaps, based on the Heston stochastic volatility model with regime switching. In comparison with all the previous studies in the literature, this research, which obtains closed-form exact solutions for variance and volatility swaps with discrete sampling times, serves several purposes. (1) It verifies the degree of validity of Elliott et al.'s [Appl. Math. Finance, 2007, 14(1), 41–62] continuous-sampling-time approximation for variance and volatility swaps of relatively short sampling periods. (2) It examines the effect of ignoring regime switching on pricing variance and volatility swaps. (3) It contributes to bridging the gap between Zhu and Lian's [Math. Finance, 2011, 21(2), 233–256] approach and Elliott et al.'s framework. (4) Finally, it presents a semi-Monte-Carlo simulation for the pricing of other important realized variance based derivatives.