Weijie Yan

I am a post-doc researcher at the Economic and Social Research Institute (ESRI Dublin). I got my Ph.D. in economics at the University of East Anglia (UEA). My area of specialty is industrial organization, health economics (pharmaceutical market), firm behaviors and competitiveness. I am currently working on various topics with firm level data. I was also a student member of the Center for Competition Policy (CCP) at UEA. Prior to coming to UEA, I got a Bachelor of Science in Statistics from the University of Hong Kong.

My CV can be found >> here.

Contact email address: weijie.yan@esri.ie & owenyanwj@gmail.com .

Research interests

My research interests are mainly in industrial organization (IO), health economics, firm behaviors and competitiveness. Some of my current research projects can be found here.

In my Ph.D. dissertation I focuses on market power and competition among UK pharmaceutical firms. In this respect, I empirically assessed entry barriers and strategic entry deterrence strategies employed by firms. I am also interested in using economic method to evaluate policy interventions. For instance, using structural demand models to estimate the consumption of antibiotics in the UK, I assessed the effectiveness of using supply-side interventions, such as a tax on a certain class of antibiotics which are prone to contributing more to antibacterial resistance, to promote use of alternative antibiotic drugs. My main skills are in econometric methods and I have experience in working with large data sets. I am also interested in Big Data techniques and applying them to my areas of research interest.

Job market paper

My job market paper has the title: "Antibacterial resistance and the cost of affecting demand: the case of UK antibiotics". It is a joint work with my supervisors Dr. Farasat Bokhari and Dr. Franco Mariuzzo. This paper has been presented in the EARIE 2017 conference in ‘Rising Star’ session (discussant: Margaret Kyle) and in the 4th EHEAPhD workshop (discussant: Lukas Kauer).

Abstract. Consumption of general purpose broad-spectrum antibiotics is associated with rising levels of antimicrobial resistance. Additionally, industry reports suggest that lack of profitability associated with narrowly targeted pathogens is a potential reason why firms are not undertaking new antibiotic related R&D. In this paper we use aggregate sales data on antibiotics from the UK to estimate a structural demand model and evaluate market performance of firms by spectral activity. We find that broad-spectrum antibiotics are more profitable than narrow-spectrum drugs, though the profitability has increased over time for both types due to a decline in marginal costs, the costs of narrow stay higher. We then simulate counterfactual scenarios to estimate the effectiveness of cost-side interventions to shift demand from broad- to narrow-spectrum drugs. Simulations show that if the marginal costs of broad-spectrum were as high as those of narrow-spectrum (say due to a tax), demand for broad-spectrum would fall by 27%, while that of narrow-spectrum would increase by 42%. However, the social cost of such a tax would be 46 million pounds in 2012 (or 565 pounds per thousand individuals per year over the ten year average) due to change in total welfare, of which around 70% is contributed by the loss of consumer welfare.

About his Ph.D thesis

My thesis "Essays on entry and market profitability in the UK pharmaceuticals" applies economic methods developed in industrial organization to assess entry barriers and profitability of the pharmaceutical market in the UK. The thesis has two parts.

The first part investigates whether incumbent firms strategically proliferate product varieties to delay and deter entry of competitors and whether such a strategy is effective to be a barrier. The investigation is conducted from three aspects : a semi-parametric non-monotonicity test between number of products and market size; a hazard rate model of entry probability, with focus on whether entry can be influenced by product varieties; and a penal data regression of incumbent's market share post entry to test whether their share is positively correlated with product varieties built prior to entry. The results suggest that product proliferation can be a barrier to entry in the UK, however, evidence on incumbents' strategic incentive is inconclusive.

The second part of the thesis focuses on the antibiotic market. Despite this market is in need for new entry because of antimicrobial resistance, research firms are leaving it. We use nested logit and random coefficients logit model to assess the profitability of the market. We then estimate the price elasticity of demand between drugs and assess policy interventions of shifting consumption away from molecules that cause larger resistance. The results suggest such interventions can be effective, but under certain conditions.

Teaching experiences

I have taught different economic courses at both undergraduate level and postgraduate level as the seminar leader, and always received good course evaluation feedback from my students: over 4/5 for each module.

Undergraduate level:

2014/5 Strategic thinking
2015/6 Intermediate economics
2017/8 Introductory econometric
2017/8 Introductory mathematics for economists

Postgraduate level:

2015/6 Economic concept
2016/7 Economic concept

Other activities

I love playing the violin. I was the first violin player in the Union Philharmonic Orchestra, University of Hong Kong Student Union, and the University of East Anglia Symphony Orchestra.

I like photography, the banner of this site is photoed by myself: UEA in the sunset, a view through the Broad. Due to the feature of Google site, you can only see the full picture when the browser window is narrow enough, or on a phone.