We examine the volatility dynamics of NYMEX natural gas futures prices via the partially overlapping time-series model of Smith (2005. Journal of Applied Econometrics, 20, 405-422). We show that volatility exhibits two important features: (1) volatility is greater in the winter than in the summer, and (2) the persistence of price shocks and, hence, the correlations among concurrently traded contracts, displays substantial seasonal and cross-sectional variation in a way consistent with the theory of storage. We demonstrate that, by ignoring the seasonality in the volatility dynamics of natural gas futures prices, previous studies have suggested sub-optimal hedging strategies.

We gratefully acknowledge insightful comments from the editor James Smith and three anonymous reviewers, which helped improve the paper. Suenaga receives financial support from the Australian Research Council Discovery Grant. Smith is a member of the Giannini Foundation of Agricultural Economics.

We examine the relationship between Internet-based health information seeking and the demand for physician services, using data collected from the 28 European Union states in 2014. Unlike previous research, our analysis distinguishes seekers of health information into those who use only non-Internet sources and those who use the Internet and possibly non-Internet sources. By comparing the frequencies of physician visits among the two groups of health information seekers and non-seekers, we infer the net association between online health information and the demand for physician services while partially controlling for the effects of concurrent seeking of offline health information. The following are the two key findings: (1) individuals’ health status and sociodemographic factors shape online and offline health information seeking patterns in similar ways; and (2) the demand for physician services is positively associated with offline health information seeking and not with online health information. The net association with online health information would be even smaller after controlling for the effect of concurrent offline health information seeking. These results suggest that extending the availability of online health information would potentially reinforce the unequal access to health information, which could create greater variation in individuals’ health management skills and benefits from health care in the long term. However, it would be associated with little or no increase in the demand for physician services, unlike the implications of previous research.

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