Habilitation von Ralf Hohlfeld

Ohne Zusammenfassung     

Testing for Unit Roots with Breaks: Evidence on the Great Crash and the Unit Root Hypothesis Reconsidered

Nelson and Plosser (1982), in a classic paper, failed to find strong evidence against the null hypothesis of a generating process with a unit autoregressive root for thirteen US macroeconomic time series. Perron (1989) claimed that such evidence was available for a majority of these series if the alternative hypothesis was of trend stationarity with a break in 1929. Zivot and Andrews (1992) treated the break date as endogenous, then finding strong evidence agcainst the null for a minority of these series. Our own analysis extends theirs by permitting a break under the null as well as the alternative hypothesis, and allowing for the sequential nature of the testing. Our empirical findings complete the circle. We find no strong evidence against the unit root hypothesis for any of the thirteen Nelson–Plosser series.     

在衰退中成长

如今,全球都笼罩在经济衰退之中.如果下一个就要轮到贵公司,你该怎么办?当然你要尽力保证企业财务的稳定.但更重要的是,你还必须了解公司在衰退结束后的目标设计.如果你知道企业的发展方向和如何实现这一目标,那么衰退时期是改善公司相对战略地位的好时机.     

Employment Contacts and Minority-White Wage Differences

We study effects of job contacts on wages in inner-city Boston in 1989 and in the 1982 NLSY. Race/Hispanicity differences in wages are not explained by an absence of contacts among minority youths. Rather, in the Boston data, lower wages of black youths are explained by lower "returns" to their contacts. In the NLSY there is little evidence of lower return to black youths' contacts, but there is evidence of lower returns to Hispanic youths' contacts.     

Large Non-Union Companies: How Do They Avoid a Catch 22?

Large non-union companies might be expected to enjoy extensive work-force flexibility deriving from their high-wage, high-involvement strategies. However, where there is a strong local union presence, this might be expected to exert a strong dampening effect on the levels of internal flexibility achieved. Such companies, fearful of union organization, could not then enjoy the freedoms that might be associated with a non-union strategy. Research conducted in the Republic of Ireland on large non-union US companies operating in the electronics industry suggests a conceptual framework indicating how a Catch-22 situation is avoided in these companies.