We present the TreeScape system which, unlike any other system known to the authors, enables the reuse of pre-computed aggregate query results involving the kinds of irregular dimension hierarchies that occur frequently in practice. The system establishes a foundation for obtaining high-performance query processing while precomputing only few aggregates. It is demonstrated how this reuse of agg...

In relational learning, predictions for an individual are based not only on its own properties but also on the properties of a set of related individuals. Many systems use aggregates to summarize this set. Features thus introduced compare the result of an aggregate function to a threshold. We consider the case where the set to be aggregated is generated by a complex query and present a framewor...

In many practical applications, the need arises to aggregate data of varying dimension. Following from the self-identity property, some recent studies have looked at the stability of aggregation operators in terms of their behavior as the dimensionality is increased from n−1 to n. We use the penalty-based representation of aggregation functions in order to investigate the conditions for weighti...

The sources of aggregate productivity growth are explored using detailed data for four-digit U.S. manufacturing industries during 1958-96 and a decomposition formula which allows to quantify the contribution of structural change. Labor productivity as well as total factor productivity are considered and the aggregation is performed with either value-added or employment shares. It is shown that ...

Many researchers are reluctant to use aggregate data in program evaluation and other policy relevant research. Aggregate data refers to data on individuals that have been averaged by year, by geographic area, by service agency, or in some other way. For example, data on the individual earnings of job training participants may be aggregated by year or student test scores may be aggregated by sch...

Surveillance is a process that observes behaviour, recognises properties and identifies individuals. It has become a commonplace phenomenon in our everyday life. Many surveillance practices depend on the use of advanced technologies to collect, store and process data. We propose (i) an abstract definition of surveillance; and (ii) an abstract definition of identity, designed to capture the comm...

Why are Italian grown-up children so reluctant to leave the parental home? In this paper we present a theoretical model predicting that this behavior can be induced by high job insecurity of children and low job insecurity of their parents. Both aggregate data for EU countries and microeconometric results, using data from the Italian Survey of Household Income and Wealth for the 1990s, are broa...

This paper provides new evidence that estimates obtained from aggregated data may not provide reliable estimates of average firm-level parameters, if the composition of producers with different levels of productivity changes over the business cycle. I examine plant-level data and show that, due to the countercyclical reallocation of output among heterogenous plants, productivity measures based ...

This article discusses the use of Bayesian methods for estimating logit demand models using aggregate data. We analyze two different demand systems: independent samples and consumer panel. Under the first system, there is a different and independent random sample of N consumers in each period and each consumer makes only a single purchase decision. Under the second system, the same N consumers ...