Which of these factors would tend to lower overall property values most in a single-family residential neighborhood?

a. construction of smaller and less valuable homes

b. homogeneity in socioeconomic levels

c. small changes in zoning laws

d. purchase of existing homes by first-time buyers?

The answer to the question above is option A: construction of smaller and less valuable homes. This is the factor that would tend to lower the overall value of the property of most single-family residential neighborhood. The more low value homes built, the more that the values of these properties becomes lower. And in time, these properties' values would lower as well because the quality is also starting to decline.