31 August 2012
Dhaval Dave and
Jose Fernandez investigate how changes in the number of autism cases at each of the 21 regional development centers in California have affected the wages and quantity of auxiliary health providers such as speech pathologists, behavioral therapists, and occupational therapists. Unlike physicians and psychologists who can diagnose autism, those providers cannot induce their own demand. The authors study whether an increase in the incidence of autism, without any increase in other mental disorders, raises the demand for auxiliary health providers and results in both higher wages and an increase in their number. Using data from the American Community Survey, they confirm that a 100 percent increase in the number of autism cases increases the wages of auxiliary health workers relative to those in non-autism health occupations by 8-to-11 percent and increases the number of providers by 7-to-15 percent the following year.
30 August 2012
Roland Fryer,
Steve Levitt,
John List, and
Sally Sadoff conducted an experiment in nine schools in Chicago Heights, IL during the 2010 school year. Teachers were randomly selected to participate in a pay-for-performance program: one set of teachers – the “Gain” group – received bonuses linked to student achievement at the end of the year; the other participating teachers – the “Loss” group – were given an identical lump sum payment at the beginning of the school year and informed that they would have to return some or all of it if their students did not meet performance targets. The researchers find that paying teachers in advance and asking them to give back the money if their students do not improve sufficiently was associated with a larger increase in math test scores among students than paying teachers after the fact if their students' test scores improved.
29 August 2012
Kevin Milligan and
David Wise try to unravel the mystery of why people are living longer and healthier lives but not necessarily working longer. They postulate that age-specific mortality rates are an indicator of health status, and therefore argue that men who have the same mortality rates in different years – but who are of different ages -- have similar capacity for work. After analyzing the employment rates of older men in a number of nations, they find that American men aged 55 to 69 in 2007 would have worked 3.7 years longer, on average, if they had worked as much as they did in 1977 at each mortality level. French men in 2007 would have worked 4.6 years longer, on average, if they had worked as much as American men at each level of mortality. In contrast, Japanese men work slightly more than American men, given levels of mortality.
28 August 2012
Texas requires school districts to offer bilingual education when they have at least 20 limited English proficient (LEP) students enrolled in a particular elementary grade and language. Using data from these districts,
Aimee Chin,
Meltem Daysal, and
Scott Imberman find that bilingual education programs do not significantly affect the standardized test scores of students with Spanish as their home language but do have positive effects on their non-LEP peers.
27 August 2012
Ulrike Malmendier,
Marcus Opp, and
Farzad Saidi collect data on all unsuccessful merger bids in the United States between 1980 and 2008 and document initial announcement effects of 15 percent for stock deals and 25 percent for cash deals. They then show that by the time of the deal's failure, the value of the target firms in stock transactions falls below its pre-announcement level while the value of the targets in cash deals remains about 15 percent above the pre-announcement level. These estimates imply that for the average cash deal completed during their sample period, approximately $78m (in 2010 dollars) is attributable to target revaluation rather than to the merger.