Dr. Paulson conducts an evaluation of an anti-poverty program among single mothers in Chicago. She finds that providing two six-hour sessions per week of free group child care reduces the likelihood that single mothers apply for federal benefits. When the program expands to Baltimore and San Antonio, Dr. Paulson does not find the same results. Which of the following factors might explain the low external validity in the first study?

a. The questions about federal benefits varied between the first study and the second study.
b. The researchers did not find enough single mothers in Baltimore and San Antonio.
c. Single mothers in Baltimore and San Antonio may have stronger networks of friends and family who can watch their children and thus the program benefit is minimal to them.
d. Single mothers in Baltimore and San Antonio were embarrassed to admit that they were receiving federal benefits.

c. Single mothers in Baltimore and San Antonio may have stronger networks of friends and family who can watch their children and thus the program benefit is minimal to them.

Explanation:

This is because, in a situation whereby a single mother has 2 children but those children where being taken care of by their grandparents. This would affect the likelihood of the single mother applying for federal benefits.

This will on the long run affected the results Dr. Paulson would get when he conducts his anti-poverty program.

countries such as spain, france and portugal colonized the region. although most of latin america was colonized by spain, the countries of portugal and france also had major influences on the region. due to war and disease, native populations were decimated.

marginal cost is a microeconomic measure that us to evaluate the extent to which the level of production of a good is sustainable in accounting, that is, to how many quantities the company plans to profit from the production of the good.

the concept of marginal cost is simple, it means the cost of producing one more item. for example, in the case of pies, the marginal cost is the cost of producing one more pie than those that have already been produced.

it is important to understand that productive activity influences marginal cost. the marginal cost of some goods can be very high, while others may be insignificant. for example, the marginal cost of producing an extra plane is very high. already the marginal cost of a water company to provide 1l more water is derisory.

in the case of pies, the cost involves the inputs, the labor and the fixed cost, which involves the fixed space of the bakery. the level of production initially has the marginal cost decreasing because there is space and manpower available. however, to produce more you have to hire more workers and buy more inputs. if physical space is limited, workers will conflict with places, inputs and their productivity will decrease, meaning there is an optimum point of production for each level of space and manpower. from this point on, the productivity of the workers will be getting smaller because of lack of space, so that the marginal cost of producing one more pie will be increasing. so, although you have not posted the chart, but if you have the answer, you can see that my explanation goes according to the marginal cost curve that will increase from the 4th pie, answer (c).