A second-tier patent system with relatively low protectability standards has been adopted by many countries, but empirical evidence on how it is used by firms israre. Using Chinese patent data, we exploit “parallel filings” – where a second-tierpatent is filed simultaneously with an invention patent – to shed light on its usein practice. The data indicate that while parallel filings appear to be inventionswith a narrower scope, they are cited more frequently in the early years and morelikely to be licensed or transferred compared to inventions protected by standardpatents. We provide evidence that parallel filing is likely a strategic choice forshort-life-cycle technologies that achieve high value early in their lifetime but decayfast. The rapid issuance of the second-tier patent facilitates knowledge diffusionand technology transfer, thereby helping the patentees capitalize on the value of fast-moving technologies. This study provides some much-needed empirical evidenceon how the quick procedure of the second-tier patent system serves short life-cycletechnologies.

We study the labor markets in China and the United States, the two largest economies in the world, by examining the evolution of their cross-sectional age-earnings profiles during the past thirty years. We find that, first, the peak age in the cross-sectional age earnings profiles, which we refer to as the “golden age,” stayed almost constant at around 45-50 in the U.S., but decreased sharply from 55 to around 35 in China; second, the age-specific earnings grew drastically in China, but stayed almost stagnant in the U.S.; third, the cross-sectional and life-cycle age-earnings profiles were remarkably similar in the U.S., but differed substantially in China. We propose and empirically implement a decomposition framework to infer from the repeated cross-sectional earnings data the experience effect (i.e., human capital accumulation over the life cycle), the cohort effect (i.e., inter-cohort human capital growth), and the time effect (i.e., changes in the human capital rental prices over time), under an identifying assumption that the growth of the experience effect stops at the end of one’s working career. The decomposition suggests that China has experienced a much larger inter-cohort productivity growth and higher increase in the rental price to human capital, but lower returns to experience, compared to the U.S. We also use the inferred components to revisit several important and classical applications in macroeconomics and labor economics, including growth accounting and the estimation of TFP growth, and the college wage premium and skill-biased technical change.

Women work less often and earn significantly less than men in Japan. We use panel data to investigate employment and earnings dynamics of single and married women over the life-cycle and build a structural model to study roles of fiscal policies in accounting for their behavior. We show that eliminating spousal deductions, social insurance tax exemptions and survivors’ pension benefits for low-income spouses would significantly raise labor supply of women and their earnings. More women would choose regular jobs rather than contingent jobs, accumulate more human capital and enjoy higher income growth. The government would earn higher net revenues and there is a welfare gain when additional taxes are transferred back.

This paper answers the following question posed by Richard Roll: Should one work less, or perhaps retire early, if her stock portfolio performs well? We show that in a standard life-cycle model the answer to both questions is yes. We solve explicitly for the endogenous retirement time and labor supply. We nd that human capital acts like a portfolio of European put options on stock. The agent's labor choice can be characterized by four regions (categorized according to the nancial wealth of the agent at a given time): retire, vacation, work, and work-forever. We show that for a constant wage when the agent's stock performs well, she will work less and retire earlier. We also nd that poorer people (those whose stock returns are worse) should 1)-invest less of their wealth in stock, and 2)-borrow heavily when their stock does badly. We nd that the conditional volatility of labor income is hump-shaped as a function of the stock price. An agent will invest fewer dollars in the stock market when she has no future labor income.