Covid-19 and child criminal exploitation in the UK: implications of the pandemic for county lines

In March 2020, the UK was placed in lockdown following the spread of the Covid-19 virus. Just as legitimate workplaces made changes to enable their employees to work from home, the illicit drugs trade also made alternative arrangements, adapting its supply models to ensure continuity of operations. Based upon qualitative interviews with 46 practitioners, this paper assesses how front-line professionals have experienced and perceived the impact of Covid-19 on child criminal exploitation and County Lines drug supply in the UK. Throughout the paper, we highlight perceived adaptations to the County Lines supply model, the impact of lockdown restrictions on detection and law enforcement activities aimed at County Lines, and on efforts to safeguard children and young people from criminal exploitation. Our participants generally believed that the pandemic had induced shifts to County Lines that reflected an ongoing evolution of the drug supply model and changes in understanding or attention because of Covid-19 restrictions, rather than a complete reconstitution of the model itself. Practitioners perceived that Covid-19 has had, and continues to have, a significant impact on some young people’s vulnerability to exploitation, on the way in which police and frontline practitioners respond to County Lines and child criminal exploitation, and on the way illegal drugs are being moved and sold.

Service quality of transit and demand-supply forecasting for ride-hailing in the Jakarta Greater Area, Indonesia

The extensive use of smartphones by individuals has led innovators to develop application-based transportation services. Ride-hailing systems have been extensively operated in more than 600 cities worldwide. With the competition between taxis and ride-hailing, the number of fleets must be regulated. Identifying factors that influence the demand of taxi and ride-hailing and how the quality transit service is very important. The aims of this research are to identify the factors that influence demand for taxis and ride-hailing and the service quality of taxis and ride-hailing service. The study identified socio-demographic and trip characteristics from 949 respondents in the Jakarta Greater area, Indonesia. Respondents interviewed about the waiting time, travel time and travel costs for the origin-destination of trips that are most often done using taxi, ride-hailing, and bus. The service quality of ride-hailing and taxi was analyzed based on the respondent’s preferences from an important-performance analysis survey. The forecasting demand of taxi and ride-hailing in the Jakarta Greater area using demand-supply model is 71,660 vehicles. The research findings are that service quality of ride-hailing is better than conventional taxis based on waiting time, travel time and travel cost variable.

Money also is sunny in a retiree’s world: financial incentives and work after retirement

This paper assesses the impact of financial incentives on working after retirement. The empirical analysis is based on a large administrative individual career data set that includes information about 2% of all German employees subject to social security or in marginal employment until age 67 and their employers in the period 1975–2014. We use the classical labor supply model and differentiate between the impact of (potential) labor and non-labor (pension entitlements) income. A Heckman-type two step selection model corrects for endogeneity. We show that labor income has a positive and non-labor income a negative impact on the decision to work after retirement. Especially individuals who can substantially increase their earnings in comparison to their pension entitlements accordingly have a higher probability to work. Men are more attracted by labor earnings incentives than women. Also individuals who work until retirement are easier attracted to work after retirement by higher labor income than those with gaps between employment exit and retirement. Our results allow the calculation of the impact of changes in taxes on labor and non-labor income and changes in earnings offers by employers on work after retirement for different demographic groups.

Research on Location Selection Strategy for Airlines Spare Parts Central Warehouse Based on METRIC

With the increased demands of airlines, it is important to study the location selection strategy for spare parts central warehouse in order to improve the allocation capacity of spare parts maintenance resources and reduce the operating costs of airlines. Based on the M/M/s/∞/∞ multiservice desk model and Multi-Echelon Technique for Recoverable Item Control (METRIC) theory, this paper proposes a spare parts supply strategy based on the spare parts pool network and establishes a location selection model for spare parts central warehouse. The particle swarm optimization (PSO) algorithm is used to iteratively optimize the location for spare parts central warehouse and adjust the location area of the central warehouse combining transportation facilities and geographical environment factors. Finally, the paper compares the operating results for multiple airlines in pooling and off-pooling states and verifies the effectiveness of the spare parts supply model and the advantages of cost control for airlines.

Using Labor Supply Elasticities to Learn about Income Inequality: The Role of Productivities versus Preferences

Using a general labor supply model in which individuals choose how much to work conditional on productivities and preferences for consumption relative to leisure, we show that the mapping from earnings and hours worked to productivities and preferences can be expressed entirely in terms of reduced-form labor supply elasticities. We investigate the roles that productivities and preferences play in driving income inequality in the United States. Benchmark labor supply elasticity estimates from the literature imply that productivities drive most income inequality. Preferences become increasingly important relative to benchmark, with larger income effects or larger differences between earnings and hours-worked elasticities. (JEL J22, J24, D31, J31, H24, H31)

Blood platelet bank inventory management: an approximate dynamic programming approach

Blood platelets are precious and highly perishable; their supply and demand suffer from significant variation. Consequently, the inventory management of platelets is an actual, contemporary prob- lem of considerable human interest. Although many researchers have solved a plethora of inventory models, their solutions have faced various challenges. This dissertation models some of these chal- lenges, alongside expenses and stock levels. This dissertation is based on four key objectives: (1) to develop a blood platelet inventory model that can represent an actual blood bank inventory, while overcoming the problem's curse of dimensionality; (2) to look for the best issuing policy based on the proposed model that can serve different incoming blood platelet demands; (3) to analyze the effect of having a new, artificial blood platelet alongside the existing natural eight blood types; and (4) to enhance the proposed model for a dual-supplied regional blood platelet bank that serves a network of hospitals. Blood platelet inventory management model is a multi-period, multi-product model that considers the eight natural blood types with uncertain demand, and deterministic lead times, alongside the artificial platelet and patients right to refuse it. The study is supported by both a review of literature and a testing data provided by the Canadian Blood Service. The findings show that modeling blood platelet inventory management, including the eight blood types and their ages, represents the actual-life model without any need for downsizing. It also leads to significantly reductions in shortages and outdates while increasing reward gained and maintaining minimal inventory levels. Compared to a single supply model, the dual supply model give less shortage and outdate rates. The regional blood bank inventory model considers the fact that patients have the right to refuse transfusion using artificial blood platelets. Finally, if the percentage of artificial supply in the inventory is more than 30% and the rate of patient acceptance is more than 30%, then both outdate and shortage percentages are below 1%.

Blood platelet bank inventory management: an approximate dynamic programming approach

Blood platelets are precious and highly perishable; their supply and demand suffer from significant variation. Consequently, the inventory management of platelets is an actual, contemporary prob- lem of considerable human interest. Although many researchers have solved a plethora of inventory models, their solutions have faced various challenges. This dissertation models some of these chal- lenges, alongside expenses and stock levels. This dissertation is based on four key objectives: (1) to develop a blood platelet inventory model that can represent an actual blood bank inventory, while overcoming the problem's curse of dimensionality; (2) to look for the best issuing policy based on the proposed model that can serve different incoming blood platelet demands; (3) to analyze the effect of having a new, artificial blood platelet alongside the existing natural eight blood types; and (4) to enhance the proposed model for a dual-supplied regional blood platelet bank that serves a network of hospitals. Blood platelet inventory management model is a multi-period, multi-product model that considers the eight natural blood types with uncertain demand, and deterministic lead times, alongside the artificial platelet and patients right to refuse it. The study is supported by both a review of literature and a testing data provided by the Canadian Blood Service. The findings show that modeling blood platelet inventory management, including the eight blood types and their ages, represents the actual-life model without any need for downsizing. It also leads to significantly reductions in shortages and outdates while increasing reward gained and maintaining minimal inventory levels. Compared to a single supply model, the dual supply model give less shortage and outdate rates. The regional blood bank inventory model considers the fact that patients have the right to refuse transfusion using artificial blood platelets. Finally, if the percentage of artificial supply in the inventory is more than 30% and the rate of patient acceptance is more than 30%, then both outdate and shortage percentages are below 1%.