Economics Insights @ CBS

We study the M_t/G/∞ queue where customers arrive according to a sinusoidal function λt = λ + A sin(2 π t/T) and the service rate is μ. We show that the expected number of customers in the system during peak congestion can be closely approximated by (λ + A)/ μ for service distributions with coefficient of variation between 0 and 1.

Generalized knowledge comes from cumulating results across studies, a process known as meta-analysis. Efficiently increasing generalized knowledge in a defined area-estimates of price or advertising, for example-is one important goal for research. Because (1) most meta-analyses are based on highly inefficient and unbalanced natural experiments or designs and (2) additional studies are costly, carefully selecting the next study is important.

Recent research on business investment decisions suggests that real investment in plant and equipment is quite sensitive to changes in the user cost of capital, pointing to the possibility that long-run changes in tax policy may have a significant impact on an economy's capital stock. Indeed, many countries have at times adopted investment tax incentives to stimulate investment. The prevalence of investment incentives suggests that local policy-makers believe these are effective in increasing investment at a reasonable cost in terms of lost revenue.