4,609 research outputs found
The effects of immigration on U.S. wages and rents: a general equilibrium approach
In this paper we document a strong positive correlation of immigration flows with
changes in average wages and average house rents for native residents across U.S.
states. Instrumental variables estimates reveal that the correlations are compatible
with a causal interpretation from immigration to wages and rents of natives.
Separating the effects of immigrants on natives of different schooling levels we find
positive effects on the wages and rents of highly educated and small effects on the
wages (negative) and rents (positive) of less educated. We propose a model where
natives and immigrants of three different education levels interact in production in a
central district and live in the surrounding region. In equilibrium the inflow of
immigrants has a positive productive effect on natives due to complementarities in
production as well as a positive competition effect on rents. The model calibrated
and simulated with U.S.-states data matches most of the estimated effects of
immigrants on wages and rents of natives in the period 1990-2005. This validation
suggests the proposed model as a useful tool to evaluate the impacts of alternative
immigration scenarios on U.S. wages and rents
The Wavelet Trie: Maintaining an Indexed Sequence of Strings in Compressed Space
An indexed sequence of strings is a data structure for storing a string
sequence that supports random access, searching, range counting and analytics
operations, both for exact matches and prefix search. String sequences lie at
the core of column-oriented databases, log processing, and other storage and
query tasks. In these applications each string can appear several times and the
order of the strings in the sequence is relevant. The prefix structure of the
strings is relevant as well: common prefixes are sought in strings to extract
interesting features from the sequence. Moreover, space-efficiency is highly
desirable as it translates directly into higher performance, since more data
can fit in fast memory.
We introduce and study the problem of compressed indexed sequence of strings,
representing indexed sequences of strings in nearly-optimal compressed space,
both in the static and dynamic settings, while preserving provably good
performance for the supported operations.
We present a new data structure for this problem, the Wavelet Trie, which
combines the classical Patricia Trie with the Wavelet Tree, a succinct data
structure for storing a compressed sequence. The resulting Wavelet Trie
smoothly adapts to a sequence of strings that changes over time. It improves on
the state-of-the-art compressed data structures by supporting a dynamic
alphabet (i.e. the set of distinct strings) and prefix queries, both crucial
requirements in the aforementioned applications, and on traditional indexes by
reducing space occupancy to close to the entropy of the sequence
Footloose Capital, Market Access, and the Geography of Regional State Aid
The global welfare implications of home market effects in trade models with imperfect competition are little understood. This paper proposes a simple model in which such implications can be easily analyzed. It shows an overall tendency of imperfectly competitive sectors to inefficiently cluster in locations that offer market access advantages. The more so the stronger the market power of firms as well as the intensity of increasing returns to scale and the lower the trade costs. As such features are likely to differ widely across sectors, those results provide theoretical ground to the promotion of regional policies that are also sectorspecific and not only region-specific as currently in the EU.economic integration, specialization, home market effect, regional disparities, regional policy, International Relations/Trade, Political Economy, F12, L13, R13,
Footloose Capital, Market Access, and the Geography of Regional State Aid
The global welfare implications of home market effects in trade models with imperfect competition are little understood. This paper proposes a simple model in which such implications can be easily analyzed. It shows an overall tendency of imperfectly competitive sectors to inefficiently cluster in locations that offer market access advantages. The more so the stronger the market power of firms as well as the intensity of increasing returns to scale and the lower the trade costs. As such features are likely to di€er widely across sectors, those results provide theoretical ground to the promotion of regional policies that are also sector-specific and not only region-specific as currently in the EU.economic integration, specialization, home market effect, regional disparities, regional policy
The happy few: the internationalisation of European firms
The 2007 report from the research network European Firms and International Markets (EFIM) is the first systematic, cross-country, firm-level research of the features of European firms that compete in international markets.
Agglomeration, Trade and Selection
This paper studies how firm heterogeneity in terms of productivity affects the balance between agglomeration and dispersion forces in the presence of pecuniary externalities through a selection model of monopolistic competition with variable mark-ups. It shows that firm heterogeneity matters. However, whether it shifts the balance from agglomeration to dispersion or the other way round depends on its specific features along the two defining dimensions of diversity: 'richness' and 'evenness'. Accordingly, the role of firm heterogeneity in selection models of agglomeration cannot be fully understood without paying due attention to various moments of the underlying firm productivity distribution.agglomeration, trade, heterogeneity, selection, economic geography
happy few: the internationalisation of European firms New facts based on firm-level evidence.
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