2,350 research outputs found
Automated census record linking: a machine learning approach
Thanks to the availability of new historical census sources and advances in record linking technology, economic historians are becoming big data genealogists. Linking individuals over time and between databases has opened up new avenues for research into intergenerational mobility, assimilation, discrimination, and the returns to education. To take advantage of these new research opportunities, scholars need to be able to accurately and efficiently match historical records and produce an unbiased dataset of links for downstream analysis. I detail a standard and transparent census matching technique for constructing linked samples that can be replicated across a variety of cases. The procedure applies insights from machine learning classification and text comparison to the well known problem of record linkage, but with a focus on the sorts of costs and benefits of working with historical data. I begin by extracting a subset of possible matches for each record, and then use training data to tune a matching algorithm that attempts to minimize both false positives and false negatives, taking into account the inherent noise in historical records. To make the procedure precise, I trace its application to an example from my own work, linking children from the 1915 Iowa State Census to their adult-selves in the 1940 Federal Census. In addition, I provide guidance on a number of practical questions, including how large the training data needs to be relative to the sample.This research has been
supported by the NSF-IGERT Multidisciplinary Program in Inequality & Social Policy at Harvard
University (Grant No. 0333403)
On the equality of Hausdorff and box counting dimensions
By viewing the covers of a fractal as a statistical mechanical system, the
exact capacity of a multifractal is computed. The procedure can be extended to
any multifractal described by a scaling function to show why the capacity and
Hausdorff dimension are expected to be equal.Comment: CYCLER Paper 93mar001 Latex file with 3 PostScript figures (needs
psfig.sty
How legislators respond to localized economic shocks: evidence from Chinese import competition
We explore the effects of localized economic shocks from trade on roll-call behavior and electoral outcomes in the US House, 1990ā2010. We demonstrate that economic shocks from Chinese import competitionāfirst studied by Autor, Dorn, and Hansonācause legislators to vote in a more protectionist direction on trade bills but cause no change in their voting on all other bills. At the same time, these shocks have no effect on the reelection rates of incumbents, the probability an incumbent faces a primary challenge, or the partisan control of the district. Though changes in economic conditions are likely to cause electoral turnover in many cases, incumbents exposed to negative economic shocks from trade appear able to fend off these effects in equilibrium by taking strategic positions on foreign-trade bills. In line with this view, we find that the effect on roll-call voting is strongest in districts where incumbents are most threatened electorally. Taken together, these results paint a picture of responsive incumbents who tailor their roll-call positions on trade bills to the economic conditions in their districts
Capital Destruction and Economic Growth: The Effects of Shermanās March, 1850-1920
Working paper.Using General William Shermanās 1864--65 military march through Georgia, South
Carolina, and North Carolina during the American Civil War, this paper studies the
effect of capital destruction on short- and long-run local economic activity, and the role
of financial markets in the recovery process. We match an 1865 US War Department
map of Shermanās march to county-level demographic, agricultural, and manufacturing
data from the 1850ā1920 US Censuses. We show that the capital destruction
induced by the March led to a large contraction in agricultural investment, farming asset
prices, and manufacturing activity. Elements of the decline in agriculture persisted
through 1920. Using information on local banks and access to credit, we argue that
the underdevelopment of financial markets played a role in weakening the recovery
The majority-party disadvantage: revising theories of legislative organization
Dominant theories of legislative organization in the U.S. rest on the notion that the majority party arranges legislative matters to enhance its electoral fortunes. Yet, we find little evidence for a short-term electoral advantage for the majority party in U.S. state legislatures. Furthermore, there appears to be a pronounced downstream majority-party disadvantage. To establish these findings, we propose a technique for aggregating the results of close elections to obtain as-if random variation in majority-party status. We argue that the results from this approach are consistent with a phenomenon of inter-temporal balancing, which we link to other forms of partisan balancing in U.S. elections. The article thus necessitates revisions to our theories of legislative organization, offers new arguments for balancing theories, and lays out an empirical technique for studying the effects of majority-party status in legislative contexts
Semi-Streaming Set Cover
This paper studies the set cover problem under the semi-streaming model. The
underlying set system is formalized in terms of a hypergraph whose
edges arrive one-by-one and the goal is to construct an edge cover with the objective of minimizing the cardinality (or cost in the weighted
case) of . We consider a parameterized relaxation of this problem, where
given some , the goal is to construct an edge -cover, namely, a subset of edges incident to all but an
-fraction of the vertices (or their benefit in the weighted case).
The key limitation imposed on the algorithm is that its space is limited to
(poly)logarithmically many bits per vertex.
Our main result is an asymptotically tight trade-off between and
the approximation ratio: We design a semi-streaming algorithm that on input
graph , constructs a succinct data structure such that for
every , an edge -cover that approximates
the optimal edge \mbox{(-)cover} within a factor of can be
extracted from (efficiently and with no additional space
requirements), where In particular for the traditional
set cover problem we obtain an -approximation. This algorithm is
proved to be best possible by establishing a family (parameterized by
) of matching lower bounds.Comment: Full version of the extended abstract that will appear in Proceedings
of ICALP 2014 track
A Time-Space Tradeoff for Triangulations of Points in the Plane
In this paper, we consider time-space trade-offs for reporting a triangulation of points in the plane. The goal is to minimize the amount of working space while keeping the total running time small. We present the first multi-pass algorithm on the problem that returns the edges of a triangulation with their adjacency information. This even improves the previously best known random-access algorithm
Crosswords at a Crossroad: The Puzzle Turns 100. What Is the Clue to Its Survival?
Celebrating the 100th anniversary of the crossword on Dec. 21, 2013 will be a dedicated, demanding and outspoken following ā an online community that may be the key to its future as a popular American pastime. The crossword puzzle has always had a tight-knit core of fans, even in its earliest years. But, for the most part, doing a crossword was a solitary pursuit. That has changed with the advent of a burgeoning fan community on the internet, a virtual community of crossword enthusiasts. It is not far-fetched to regard the saga of the crossword as a microcosm of modern community building, a case history on how a traditional pastime can adapt to new media.
In this paper, my intent is to show ā through research, interview and my own longtime amateur participation in puzzling ā the importance of community to a leisure-time pursuit; and specifically how cyber-fans use their collective voice to influence crossword output both creatively and economically. Creatively because blogs and other web resources have raised the volume and reach of an active crossword fan base, allowing it to exert more far-reaching pushback on puzzle creators and content. Economically because with the dramatic decline of the crossword\u27s longtime medium, the print newspaper, this traditionally paper-and-pencil pastime is moving online.
Complicating the discussion is a growing generation gap, a tug-of-war between younger and older puzzlers for what they see as relevant and acceptable content. Thus, the crossword is at a crossroad: an older generation forms a core part of the fan base while younger puzzlers are charged with adapting and shaping the crossword for survival in the future
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