Using the Pack‐and‐a‐Half Rule to Eliminate Backroom Inventories in Retail Operations

In the retail industry, backroom inventories are typically associated with higher labor costs and greater operational complexity. Thus, retailers look for ways to eliminate backroom inventories. A heuristic used for this purpose is the pack‐and‐a‐half rule which suggests that the shelf space allocated for a product should be at least 50% larger than the case pack quantity in which the product is delivered. Despite its popularity among retailers, the pack‐and‐a‐half rule has been ignored in the academic literature. We introduce the pack‐and‐a‐half rule, assess its impact on a retailer's profits, identify cost, demand, and product characteristics driving this impact, and propose a modification. Based on an analysis of data obtained from a retailer on 1,986 SKUs in 20 categories, we find that the pack‐and‐a‐half rule decreases a retailer's profits, on average, by 10% when applied uniformly across all SKUs. Further, this decrease is significantly affected by product depth, product width, demand elasticity, case pack quantity, and inventory carrying cost. Finally, we develop a set of modifications based on these variables where the pack‐and‐a‐half rule is applied selectively and in a stepwise fashion. These modifications limit the decrease in a retailer's profits to a range between 6% and 7%.     

The Impact of Employment on Parental Coresidence

We examine the extent to which parents use housing and shared living arrangements as a form of risk‐sharing for their adult children, using detailed data on children and parents in the Health and Retirement Study for 1998–2012. On average, a young man moving from full‐time to nonemployment raises the likelihood of coresiding with a parent by 1.5 percentage points; moving from full‐time employment to being part‐time employed raises the likelihood of coresiding with a parent by 2 percentage points. The implied elasticity of parental coresidence with respect to the son's income is ‐1.1; for daughters, the elasticity is ‐0.5.     

Sparse Signals in the Cross‐Section of Returns

This paper applies the Least Absolute Shrinkage and Selection Operator (LASSO) to make rolling one‐minute‐ahead return forecasts using the entire cross‐section of lagged returns as candidate predictors. The LASSO increases both out‐of‐sample fit and forecast‐implied Sharpe ratios. This out‐of‐sample success comes from identifying predictors that are unexpected, short‐lived, and sparse. Although the LASSO uses a statistical rule rather than economic intuition to identify predictors, the predictors it identifies are nevertheless associated with economically meaningful events: the LASSO tends to identify as predictors stocks with news about fundamentals.     

EDITORIAL: TAX REFORM AND SIMPLIFICATION

Major tax reform to simplify the UK tax system is possible. Merging income taxes, social security taxes and corporation tax into only a single flat-rate of tax on all incomes would be a radical start. Avoiding taxes on income and expenditure which are 'too high' requires major reductions in government spending, mainly on the welfare state. Given the political will, over a period of years we really can hugely improve the UK tax system.     

A Paleoeconomic Theory of Co-Evolution and Extinction of Domesticable Animals

One Pleistocene mystery is why early North Americans eradicated their large, potentially domesticable animals (e.g., horses), whereas early Europeans did not. A commonly‐held hypothesis is that European species were evasive due to co‐evolution with hominids, whereas North American animals were naïve and unable to adapt quickly enough when experienced human hunters arrived from Eurasia. We explore this hypothesis with a paleoeconomic model of co‐evolution that integrates human hunting investments and wildlife population responses. We find that investments in hunting ability, based on the relative scarcity of prey species, could have mattered more than wildlife ‘naivety’ in explaining the extinction.