Random Drug Testing of TANF Recipients is Costly, Ineffective and Hurts Families

Legislators in a number of states have proposed to test all TANF recipients for drug use. This brief explains that random drug testing may be unconstitutional, and is a costly and ineffective way to identify individuals in need of substance abuse treatment. Screening, targeted testing programs, and enhanced treatment options are a better approach to helping TANF families affected by substance abuse

Using Program Synthesis for Program Analysis

In this paper, we identify a fragment of second-order logic with restricted quantification that is expressive enough to capture numerous static analysis problems (e.g. safety proving, bug finding, termination and non-termination proving, superoptimisation). We call this fragment the {\it synthesis fragment}. Satisfiability of a formula in the synthesis fragment is decidable over finite domains; specifically the decision problem is NEXPTIME-complete. If a formula in this fragment is satisfiable, a solution consists of a satisfying assignment from the second order variables to \emph{functions over finite domains}. To concretely find these solutions, we synthesise \emph{programs} that compute the functions. Our program synthesis algorithm is complete for finite state programs, i.e. every \emph{function} over finite domains is computed by some \emph{program} that we can synthesise. We can therefore use our synthesiser as a decision procedure for the synthesis fragment of second-order logic, which in turn allows us to use it as a powerful backend for many program analysis tasks. To show the tractability of our approach, we evaluate the program synthesiser on several static analysis problems.Comment: 19 pages, to appear in LPAR 2015. arXiv admin note: text overlap with arXiv:1409.492

Asymmetric Price Adjustment and Consumer Search: An Examination of the Retail Gasoline Market

It has been documented that retail gasoline prices respond more quickly to increases in wholesale price than to decreases. However, there is very little theoretical or empirical evidence identifying the market characteristics responsible for this behavior. This paper presents a new theoretical model of asymmetric adjustment that empirically matches observed retail gasoline price behavior better than previously suggested explanations. I develop a "reference price" consumer search model that assumes consumers' expectations of prices are based on prices observed during previous purchases. The model predicts that consumers search less when prices are falling. This reduced search results in higher profit margins and therefore causes a slower price response to cost decreases than to cost increases. I then develop testable implications that distinguish my model from two alternative explanations of asymmetric adjustment. The first is a model in which firms temporarily collude using past prices as a focal price. The second theory suggests that increases in wholesale cost volatility reduce consumer search behavior. Using a panel of gas station prices, I estimate the response pattern of prices to a change in costs. Estimates are consistent with the predictions of the reference price search model and contradict the previously suggested explanations of asymmetric price adjustment.

Parallel Importation and Service Quality: An Empirical Investigation of Competition between DVDs and Cinemas in New Zealand

Investigations into the causes and effects of parallel importing have concentrated on price discrimination but arbitrage can also occur on non-price dimensions. Using a natural experiment in the New Zealand film distribution industry between May 1998 and November 2001 we examine the effect of parallel importing on quality as it relates to the timing of the availability of film media. We demonstrate that a) cinema revenues were undermined as consumers substituted viewing films on parallel imported DVDs for thecinema format and b) that studios responded to the threat of parallel imported DVDs by bringing forward the release of films into New Zealand cinemas. The reduced delay between US and New Zealand cinematic release dates is shown to be consistent with the introduction of competition when timing is a dimension of quality and choice. We conclude that parallel importation of DVDs almost certainly resulted in a net increase in welfare in New Zealand