Anomalous waiting times in high-frequency financial data

In high-frequency financial data not only returns, but also waiting times between consecutive trades are random variables. Therefore, it is possible to apply continuous-time random walks (CTRWs) as phenomenological models of the high-frequency price dynamics. An empirical analysis performed on the 30 DJIA stocks shows that the waiting-time survival probability for high-frequency data is non-exponential. This fact imposes constraints on agent-based models of financial markets.     

Mortgage affordability and entrepreneurship: Evidence from spatial discontinuity in Help-to-Buy equity loans

We exploit a policy change in the UK Help-to-Buy (HTB) equity loan scheme in order to identify the causal link between mortgage affordability and entrepreneurship activity at the local level. We contribute to the literature on the relationship between housing finance and entrepreneurship by demonstrating the impact of government equity loans on entrepreneurship through the release of trapped liquidity. When less equity is required to buy a house, households could use the ‘additional’ liquidity to start a business. We use a spatial discontinuity in treatment methodology to take advantage of the reform of the Help-to-Buy scheme in 2016, which increased the limit of equity loans provided in London. By using data on business population at the postcode sector level, we are able to measure the impact of the new policy by comparing similar areas on the opposite sides of the Greater London Authority boundary. Our results show that an increase in mortgage affordability fosters entrepreneurial activity in affected areas by 20%, resulting in 1 more start-up on average per postcode per year. The new businesses are mainly single-plant micro enterprises in capital intensive sectors with low income volatility.