Got it
We use Google Analytics in compliance with German Data Protection Law. The site gathers data for the sole purpose of improving its services. You're able to decline now or later. By using our services, you agree to our use of cookies. You'll find more information here.

Data Set Description

When permitted by law, employers sometimes state the preferred age and gender of their employees in job ads. The researchers study the interaction of advertised requests for age and gender on one Mexican and three Chinese job boards, showing that firms’ explicit gender requests shift dramatically away from women and towards men when firms are seeking older (as opposed to younger) workers. This ‘age twist’ in advertised gender preferences occurs in all four of our datasets and survives controls for occupation, firm, and job title fixed effects.

Chinese Data

The two new Chinese data sources used are job boards serving the city of Xiamen. In part because Xiamen was one of the five economic zones established immediately after China’s 1979 economic reforms, it is highly modernized relative to other Chinese cities, with an economy based on electronics, machinery and chemical engineering. One of these job boards, XMZYJS (the Xia-Zhang-Quan city public job board,, is operated directly by government employees of the local labor bureau. Like state-operated Job Centers in the U.S., XMZYJS has a history as a brick-and-mortar employment service. XMZYJS’s mandate is to serve the less-skilled portion of the area’s labor market, and operates purely as a jobposting service: workers cannot post resumes or apply to jobs on the site. In fact, while XMZYJS now posts all its job ads online, many of these ads are viewed in XMZYJS‘s offices by workers who visit in person. This is done both on individual computer terminals and on a large electronic wall display. Applications are made by calling the company that placed the ad or by coming to a specific window on XMZYJS’s premises that has been reserved by the employer at a posted date and time.

The second Xiamen-based job board, XMRC (, is a for-profit, privately-operated company that is sponsored by the local government. Its mandate is to serve the market for skilled workers in the Xiamen metropolitan area. XMRC operates like a typical U.S. job board: both job ads and resumes are posted online, workers can submit applications to specific jobs via the site, and firms can contact individual workers through the site as well.

By design, XMZYJS aggregates job postings from all local and specialized job boards for less-skilled workers in the metropolitan area, and XMRC is the main job board for skilled workers in the area. While there is potentially some cross-posting of job ads across the two sites, descriptive statistics on the types of jobs on offer suggest the sites do, indeed, serve very different populations. Like all our data sets, XMZYJS and XMRC serve private sector employers almost exclusively. Recruiting for public sector jobs, and most recruiting for State-Owned-Enterprises (SOEs) takes place via a different process.

The third Chinese database represents as the third-largest Internet job board in China; it operates nationally and serves workers who on average are considerably more skilled than even those on XMRC. This sample is based on all unique ads posted in four five-week observation periods in 2008-2010. In contrast to XMRC and XMZYJS where the data were supplied by the job boards, the Zhaopin data were collected by a web crawler. The sample is based on all unique ads posted in four five-week observation periods in 2008-2010.

The Chinese data have 141,188, 39,727, and 1,051,038 ads in the XMZYJS, XMRC and Zhaopin samples respectively.

Mexican Data

The Mexican data allows to ascertain whether main results extend to a nation with different economic conditions, labor market institutions and culture. The Mexican data is a sample of job ads posted on Of the new data sets explored, the Computrabajo data are most similar to Zhaopin in the sense that they come from a national online site that disproportionately serves highly skilled workers. To construct an analysis sample from the Computrabajo website, the authors collected advertisements daily for approximately 18 months between early 2011 and mid-2012 using a web crawler. Both the standardized fields and the open text portions of each ad were parsed to extract variables for the analysis.

Computrabajo analysis sample contains 90,487 ads.

Date Created: 2019-11-25

Scope of Data Set


Time Periods: 2008 - 2012


Helleseter, M. D., Kuhn, P., & Shen, K. (2018). The Age Twist in Employers’ Gender Requests: Evidence from Four Job Boards. Research Data Center of IZA (IDSC). Version 1.0. doi:10.15185/izadp.9891.x

Researchers working with the “The Age Twist in Employers´ Gender Requests” are obligated to acknowledge the data base and its documentation within their publications, including the DOI, by using this reference.


IZA Discussion Paper(s)


Restricted Access

  1. Helleseter, Miguel Delgado
  2. Kuhn, Peter J.
  3. Shen, Kailing

Access to the data is provided to non-for-profit research, replication and teaching purposes. The data is available from the Research Data Center (IDSC) of IZA through remote processing via JoSuA.
Remote access is an option when data are not directly available to researchers. JoSuA is the IDSC's web based solution which allows remote researchers to compute against sensitive or proprietary data by sending their code to the data when the data may not leave the premises of a data provider/custodian.
Please contact IDSC for any access requests.


Geographic Coverage: