预计5类包装机械备受市场青睐

包装机械业是包装工业的配套行业,在轻工机械行业中占有重要的地位.多年来,包装机械为包装业提供了重要的技术保障,对包装业的发展起着重要的作用.越来越多的包装业人士认为：包装业的发展出路在于包装机械的发展.试想在十多年前,我国包装机械行业技术非常落后,我国包装行业大量进口包装机械,在此同时,包装机械行业也在吸收消化国外先进技术的基础上不断创新,如今已形成了完整的行业体系,包装机械的技术水平也不断提高,不仅满足了国内的需要,有不少包装机械还出口创汇.然而,相对于国外包装机械的发展,我国仍有不小的差距,为此,今后一个时期我国包装业正面临着大的发展机遇,所以包装机械也将会有较大的发展.根据目前的现状和国内的需求情况,以下五类包装机械将会出现较大的发展.     

How Productive Are Economics and Finance PhDs?

This article analyses the research productivity of more than 200 individuals in academe with a PhD in economics and finance from (mostly) Australian universities. We find the number of publications accumulates linearly with experience, while citations increase exponentially, pointing to network effects. Panel regressions indicate: (1) the key role of experience in determining research outcomes; (2) the usual quadratic approach substantially under-estimates the role of diminishing returns to experience; (3) the university where an individual works is mostly unimportant for publications and citations. ‘Prime academic age’, when research has maximum impact, is attained about 11 years after the PhD.     

The Market for Economics and Finance PhDs

This paper presents new information about the post-graduation activities of those with a PhD in economics and finance from an Australian university. Approximately 40 per cent have an academic job, while the other 60 per cent work elsewhere or engage in other activities. The analysis includes origin‒destination networks for both the academic and non-academic markets, the determinants of earnings and measures of overqualification and underemployment. The findings of the paper can provide guidance for those completing or contemplating PhD studies.     

大气污染防治增加了企业税负吗

《京津冀及周边地区2017年大气污染防治工作方案》将"2+26"城市确定为京津冀大气污染传输通道城市进行联合防治，基于此，文章以2013-2019年"2+26"城市所在省市的A股上市公司为研究对象，运用双重差分法检验"2+26"城市大气污染联合防治行动对企业税负的影响。研究结果表明，对"2+26"城市而言，大气污染联合防治行动使得企业税负显著增加。区分企业所在城市规模、是否属于污染密集型行业、企业所有制性质的异质性分析发现，大气污染联合防治行动对非污染密集型行业企业、国有企业以及位于小规模城市的企业税负影响更大。