Automatic extraction of 1D barcodes from video scans for drone-assisted inventory management in warehousing applications

The widespread use of barcodes has significantly contributed to accurate, efficient and economic inventory management in warehouses and distribution centres. However, its efficiency has always been limited by the primary method of reading barcodes with a handheld laser scanner. Compared with this reading by line-of-sight at close proximity, vision-based barcode reading algorithms can further improve efficiency, particularly if accompanied by automated data collection platforms such as drones. This paper introduces algorithms that are able to automatically extract barcodes from video data, and verifies their feasibility and promise for inventory management in warehousing applications. Three key techniques corresponding to different recognition levels are proposed: For a known barcode region, a Harris corner detector and Hough transform-based algorithm is applied to quickly estimate the angle by which the frame area needs to rotate to orient the bars vertically for information extraction. Then, the idea of exploiting connectivity and geometry property of barcode areas is proposed to directly recognise multiple barcode regions in a single video frame to eliminate reading difficulties resulting from interactive influence of multiple juxtaposed barcodes, and to save computation time by only processing frame areas of interest for valid barcodes. In addition, a histogram difference-based fast extraction strategy is designed to further improve efficiency by reducing duplicate information processing. Finally, the performance of each technique is evaluated by analysing video data from a large logistics warehouse, demonstrating satisfactory performance in inventory management applications.     

Gold and the US dollar: Hedge or haven?

Using a model of dynamic conditional correlations covering 23 years of weekly data for 16 major dollar-paired exchange rates, this paper addresses a practical investment question: Does gold act as a hedge against the US dollar, as a safe haven, or neither? Key findings are as follows. (i) During the past 23 years gold has behaved as a hedge against the US dollar. (ii) Gold has been a poor safe haven. (iii) In recent years gold has acted, increasingly, as an effective hedge against currency risk associated with the US dollar.     

Location and ownership of public goods

We introduce location choice for the public good in the property rights framework. We find that it can be optimal to separate location from ownership.     

ALLOWING FOR JUMP MEASUREMENTS IN VOLATILITY: A HIGH‐FREQUENCY FINANCIAL DATA ANALYSIS OF INDIVIDUAL STOCKS

Following recent advances in the non‐parametric realized volatility approach, we separately measure the discontinuous jump part of the quadratic variation process for individual stocks and incorporate it into heterogeneous autoregressive volatility models. We analyse the distributional properties of the jump measures vis‐à‐vis the corresponding realized volatility ones, and compare them to those of aggregate US market index series. We also demonstrate important gains in the forecasting accuracy of high‐frequency volatility models.     

The asymmetric effects of tariffs on intra-firm trade and offshoring decisions

This paper studies the effects of tariffs on intra-firm trade. Building on the Antràs and Helpman (2004) North–South theoretical framework, I show that higher Northern tariffs reduce the incentives for outsourcing and offshoring, while higher Southern tariffs have the opposite effects. I also show that increased offshoring and outsourcing imply a decrease in the ratio of Northern intra-firm imports to total imports, an empirically testable prediction. Using a highly disaggregated dataset of U.S. (the North) imports and relevant U.S. and foreign tariffs, I find robust evidence to support the model's predictions.     

Job Polarization and Task‐Biased Technological Change: Evidence from Sweden, 1975–2005

In this paper, we show that between 1975 and 2005, Sweden exhibited a pattern of job polarization with expansions of the highest‐ and lowest‐paid jobs compared to middle‐wage jobs. The most popular explanation for such a pattern is the hypothesis of task‐biased technological change, where technological progress reduces the demand for routine middle‐wage jobs but increases the demand for non‐routine jobs located at the tails of the job–wage distribution. However, our estimates do not support this explanation for the 1970s and 1980s. Stronger evidence for task‐biased technological change, albeit not conclusive, is found for the 1990s and 2000s. In particular, there is both a statistically and economically significant growth of non‐routine jobs and a decline of routine jobs. However, results for wages are mixed; while task‐biased technological change cannot explain changes in between‐occupation wage differentials, it does have considerable explanatory power for changes in within‐occupation wage differentials.     

Does having more children increase the likelihood of parental smoking? Evidence from Vietnam

Evidence has shown that parental smoking can cause health problems for children. It might be expected that parents who are aware of the harmful effects of second-hand smoke will reduce their smoking, especially as they have more children. However, based on instrumental variable regressions using data from the 2006 and 2008 Vietnam Household Living Standard Surveys, we find a strongly positive and significant effect of the number of children on the probability of tobacco smoking in households in Vietnam. An additional child increases the probability of tobacco consumption in the household by approximately 15%. These findings imply low levels of awareness of the harmful effects of second-hand smoke on children’s health in Vietnam, and indicate the need for policy action to disseminate knowledge on the harmful effects of smoking.     

Nonparametric fixed effects model for panel data with locally stationary regressors

We develop methods for inference in nonparametric time-varying fixed effects panel data models that allow for locally stationary regressors and for the time series length $T$ and cross-section size $N$ both being large. We first develop a pooled nonparametric profile least squares dummy variable approach to estimate the nonparametric function, and establish the optimal convergence rate and asymptotic normality of the resultant estimator. We then propose a test statistic to check whether the bivariate nonparametric function is time-varying or the time effect is separable, and derive the asymptotic distribution of the proposed test statistic. We present several simulated examples and two real data analyses to illustrate the finite sample performance of the proposed methods.     

Well-being effects of self-employment: A spatial inquiry

Our paper presents an empirical analysis of entrepreneurial well-being using a large-scale longitudinal household survey from the UK that tracks almost 50,000 individuals across seven waves over the period 2009–2017, as well as a number of exploratory case studies. We contribute to the existing literature by investigating how entrepreneurial well-being varies across locations along the urban-rural continuum, and across wealthy-deprived neighbourhoods. We use a Coarsened Exact Matching (CEM) approach to compare the well-being outcomes of individuals who switch into self-employment from waged employment, and show that entrepreneurial well-being, in the form of job satisfaction, is significantly higher for those living in semi-urban locations, relative to those living in urban and rural locations. We argue that semi-urban locations provide an optimal combination of ease of doing business and quality of life. Our results also show that individuals in wealthy neighbourhoods who switch into self-employment experience higher job satisfaction than otherwise comparable individuals living in materially deprived neighbourhoods, although the latter experience greater levels of life satisfaction following the switch.     

Australia's Carbon Tax: An Economic Evaluation

Australia's carbon tax has been in place since July 2012. Following the 2013 federal election and change of government, it is likely that the tax will be abolished. This paper evaluates Australia's carbon tax experience and draws lessons for policymakers in other jurisdictions who may be considering following the Australian example and implementing their own carbon taxes or cap and trade schemes. Overall, the policy was poorly thought through, badly implemented, and lacked majority public support before it began. Australia's carbon tax experience is an interesting case study in how not to go about implementing climate change policy.