The Impact of Unionization on Establishment Closure: A Regression Discontinuity Analysis of Representation Elections

Using data on more than 27,000 establishments (1983-1999) in the United States, this paper produces estimates of the causal effect of unionization of employer closure by exploiting the fact that most employers become 'unionized' as a partial consequence of a secret ballot election among the workers. If employers where unions barely won the election (e.g. by one vote) are ex ante comparable in all other ways to employers where unions barely lost (by one vote), differences in their subsequent outcomes should represent the true impact of union recognition. The regression discontinuity analysis finds little or no union effect on short- and long-run employer survival rates over 1- to 18-year horizons. We thus conclude that evidence of large effects of unions would more likely be found 1) along the within-employer (intensive margin) of employment and/or 2) in analyses of union threat effects.

Economic Impacts of Unionization on Private Sector Employers: 1984-2001

Economic impacts of unionization on employers are difficult to estimate in the absence of large, representative data on establishments with union status information. Estimates are also confounded by selection bias, because unions could organize at highly profitable enterprises that are more likely to grow and pay higher wages. Using multiple establishment-level data sets that represent establishments that faced organizing drives in the U.S. during 1984-1999, this paper uses a regression discontinuity design to estimate the impact of unionization on business survival, employment, output, productivity, and wages. Essentially, outcomes for employers where unions barely won the election (e.g. by one vote) are compared to those where the unions barely lost. The analysis finds small impacts on all outcomes that we examine; estimates for wages are close to zero. The evidence suggests that at least in recent decades the legal mandate that requires the employer to bargain with a certified union has had little economic impact on employers, because unions have been somewhat unsuccessful at securing significant wage gains.

Spitz and wingless, emanating from distinct borders, cooperate to establish cell fate across the engrailed domain in the drosophila epidermis

A key step in development is the establishment of cell type diversity across a cellular field. Segmental patterning within the Drosophila embryonic epidermis is one paradigm for this process. At each parasegment boundary, cells expressing the Wnt family member Wingless confront cells expressing the homeoprotein Engrailed. The Engrailed-expressing cells normally differentiate as one of two alternative cell types. In investigating the generation of this cell type diversity among the 2-cell-wide Engrailed stripe, we previously showed that Wingless, expressed just anterior to the Engrailed cells, is essential for the specification of anterior Engrailed cell fate. In a screen for additional mutations affecting Engrailed cell fate, we identified anterior open/yan, a gene encoding an inhibitory ETS-domain transcription factor that is negatively regulated by the Rasl-MAP kinase signaling cascade. We find that Anterior Open must be inactivated for posterior Engrailed cells to adopt their correct fate. This is achieved by the EGF receptor (DER), which is required autonomously in the Engrailed cells to trigger the Ras1-MAP kinase pathway. Localized activation of DER is accomplished by restricted processing of the activating ligand, Spitz. Processing is confined to the cell row posterior to the Engrailed domain by the restricted expression of Rhomboid. These cells also express the inhibitory ligand Argos, which attenuates the activation of DER in cell rows more distant from the ligand source. Thus, distinct signals flank each border of the Engrailed domain, as Wingless is produced anteriorly and Spitz posteriorly. Since we also show that En cells have the capacity to respond to either Wingless or Spitz, these cells must choose their fate depending on the relative level of activation of the two pathways.Louise O’Keefe, Scott T. Dougan, Limor Gabay, Erez Raz, Ben-Zion Shilo and Stephen DiNard

Localized Excitons and Breaking of Chemical Bonds at III-V (110) Surfaces

Electron-hole excitations in the surface bands of GaAs(110) are analyzed using constrained density-functional theory calculations. The results show that Frenkel-type autolocalized excitons are formed. The excitons induce a local surface unrelaxation which results in a strong exciton-exciton attraction and makes complexes of two or three electron-hole pairs more favorable than separate excitons. In such microscopic exciton "droplets" the electron density is mainly concentrated in the dangling orbital of a surface Ga atom whereas the holes are distributed over the bonds of this atom to its As neighbors thus weakening the bonding to the substrate. This finding suggests the microscopic mechanism of a laser-induced emission of neutral Ga atoms from GaAs and GaP (110) surfaces.Comment: submitted to PRL, 10 pages, 4 figures available upon request from: [email protected]