In experimental designs with nested structures entire groups (such as schools) are often assigned to treatment conditions. Key aspects of the design in these cluster randomized experiments include knowledge of the intraclass correlation structure and the sample sizes necessary to achieve...

The paper responds to three charges: 1. Educational research has not made a contribution to instructional practice because researchers produce articles in journals rather than viable, well-engineered, instructional products, 2. Educational researchers are training teachers who simply accept...

This paper uses quasi-experimental variation in payroll tax rates in Finland to investigate how firms use their input factors. We find that higher payroll tax rates lead to large employment responses and have no effects on employee-level earnings. As payroll taxes increase, firms substitute away...

This paper uses quasi-experimental variation in payroll taxes to estimate their incidence and investigate how firms use their input factors. We find that higher payroll tax rates lead to large employment responses and have no effects on employee earnings. As payroll taxes increase, firms...

This paper uses quasi-experimental variation in payroll taxes to estimate their incidence and investigate how firms use their input factors. We find that higher payroll tax rates lead to large employment responses and have no effects on employee earnings. As payroll taxes increase, firms...