What are the welfare implications of placing restrictions on internal migration? Given externalities in location choices, the answer is ambiguous. This paper empirically examines what is presumably the largest government intervention in internal migration in human history--the Hukou system in...

Small firms dominated the American economy in the nineteenth century, and still dominate in many developing economies today. This paper tests whether geographic market segmentation due to underdeveloped intracity transportation technology precludes the emergence of large retail/wholesale stores....

How does a relaxation of migration restrictions affect labor-market outcomes of incumbent migrants? In this paper, we answer this question by studying a significant internal migration policy change in China: the 2014 hukou reform. This reform substantially removed the migration barriers of...

How does an area’s proximity to big cities affect its growth? Using county-level data from China for 1990–2020, we find that an area’s being close to big cities (in the 150–250 km range) reduces the decadal population growth rate by 2.8–3.8 percentage points. Initial agricultural...

Ultrasound-triggered sonodynamic therapy has shown great promising for the treatment of tumors, however, only few clinical reports describe the use of sonodynamic therapy, which results from that the traditional sonosensitizers tend to suffer from very poor efficiency combined with low retention...

Purpose – The purpose of this paper is to present a control system for a heavy duty industrial robot, including both the control structure and algorithm, which was designed and tested. Design/methodology/approach – An industrial PC with TwinCAT real‐time system is chosen as the motion...