Economic data with substantial seasonality are likely to have unit roots in more than one frequency. Using non-alcoholic beverage expenditure data from the United Kingdom, we empirically show that the absence of unit roots in one frequency (e.g. monthly) does not imply the absence of unit roots...

This paper considers the estimation and testing of demand systems when the number of sample goods is smaller than the number of commodity choices available to consumers. In this case, the demand system is incomplete. The large majority of papers that appeared in the literature specifies and...

The paper presents an estimator of the errors-in-variables in multiple regressions using only first and second-order moments. The consistency property of the estimator is explored by Monte Carlo experiments. Based on these results, we conjecture that the estimator is consistent. The proof of...

Several recent papers have used annual changes and monthly data to estimate demand systems. Such use of overlapping data introduces a moving average error term. This paper shows how to obtain consistent and asymptotically efficient estimates of a demand system using seasonally differenced data....