Dear Tutor, please choose the right answers only without explanation. Thank you.

a)

Consider the study by Gruber (2004) on the effects of unilateral divorce laws (UDL) in the USA. Which of the following could pose a problem for Gruberis ability to identify the causal effects of UDL on family structures and educational attainment, given that Gruber controls in his regressions for state and year xed effects as well as statespecic linear time trends? 0a\" The introduction of UDL in one state does not necessarily make divorce more socially acceptable in other states and thus divorce costs in terms of reputation would stay the same for states in the control group. States that introduce UDL simultaneously introduce tax de- ductibles for married couples and hence the value of marriage for spouses changes. 0-2. The majority of states that did not introduce UDL early were governed by Republicans which indicates level differences in average political and ethical preferences of state electorates and populations that could be correiated with the adoption of UDL. O d. States with rising divorce rates are no different from other states in their likelihood to introduce UDL early