This paper examines an economy in which aggregate shocks are not dispersed equally throughout the population. Instead, while these shocks affect all individuals ex ante, they are concentrated among a few ex post. The equity premium in genera) depends on the concentration of these aggregate shocks; it follows that one cannot estimate the degree of risk aversion from aggregate data alone. These f...

In this paper we present a new approach for studying aggregations in the context of database query languages. Starting from a broad de nition of aggregate function, we address our investigation from two di erent perspectives. We rst propose a declarative notion of uniform aggregate function that refers to a family of scalar functions uniformly constructed over a vocabulary of basic operators by...

In this paper we introduce generalized projections (GP s), an extension of duplicateeliminating projections, that capture aggregations, groupbys, duplicate-eliminating projections (distinct), and duplicate-preserving projections in a common uni ed framework. Using GP s we extend well known and simple algorithms for SQL queries that use distinct projections to derive algorithms for queries using...

Sector-level Phillips curves are estimated in French data. There is considerable heterogeneity across sectors, with vastly different estimates of the backward looking component of inflation and the duration of nominal rigidities. A multi-sector model of inflation dynamics is calibrated on the basis of these sectoral estimates. Aggregate inflation, simulated on the basis of heterogeneous sectors...

We investigate a range of music recommendation algorithm combinations, score aggregation functions, normalization techniques, and late fusion techniques on approximately 200 million listening events collected through Last.fm. The overall goal is to identify superior combinations for the task of artist recommendation. Hypothesizing that user characteristics influence performance on these algorit...

In one approach to automatic di erentiation, the range of a function is generalized from a single real value to an aggregate representing the values of the function and one or more derivatives. The operations and functions of elementary analysis are extended to these aggregates so as to preserve the validity of the derivatives. In this paper we develop a recursive approach to de ning the necess...

I show that aggregate-taking behavior is often evolutionarily stable for finite population in symmetric games in which payoff depends only on own strategy and an aggregate. I provide economic examples exhibiting this phenomenon.

We consider the problem of resource sharing when processing large numbers of continuous queries. We specifically address sliding-window aggregates over data streams, an important class of continuous operators for which sharing has not been addressed. We present a suite of sharing techniques that cover a wide range of possible scenarios: different classes of aggregation functions (algebraic, dis...

SUOWA operators are a new family of aggregation functions that simultaneously generalize weighted means and OWA operators. Semi-uninorms, which are an extension of uninorms by dispensing with the symmetry and associativity properties, play a fundamental role in their definition. In this paper we show several procedures to construct semi-uninorms. The first one allows us to obtain continuous sem...

Over time, economic statistics are refined. This means that newer data is typically less well measured than old data. Time variation in measurement error like this influences how forecasts should be made. We show how modelling the behaviour of the statistics agency generates both an estimate of this time variation and an estimate of the absolute amount of uncertainty in the data. We apply the m...