Research Methods in Economics

Rewrite the following abstract such that it does not exceed 150 words. Make sure to respect the rules and the tips suggested in the Cochranes Guide and the Neugeboren book.

The Gender Wage Gap: Extent, Trends, and Explanations
Francine D. Blau, Lawrence M. Khan
Link to the full paper: https://www.nber.org/papers/w21913

Abstract
Using PSID microdata over the 1980-2010, we provide new empirical evidence on
the extent of and trends in the gender wage gap, which declined considerably over
this period. By 2010, conventional human capital variables taken together explained
little of the gender wage gap, while gender differences in occupation and industry
continued to be important. Moreover, the gender pay gap declined much more slowly
at the top of the wage distribution that at the middle or the bottom and by 2010 was
noticeably higher at the top. We then survey the literature to identify what has been
learned about the explanations for the gap. We conclude that many of the traditional
explanations continue to have salience. Although human capital factors are now
relatively unimportant in the aggregate, womens work force interruptions and shorter
hours remain significant in high skilled occupations, possibly due to compensating
differentials. Gender differences in occupations and industries, as well as differences
in gender roles and the gender division of labor remain important, and research based
on experimental evidence strongly suggests that discrimination cannot be discounted.
Psychological attributes or noncognitive skills comprise one of the newer
explanations for gender differences in outcomes. Our effort to assess the quantitative
evidence on the importance of these factors suggests that they account for a small to
moderate portion of the gender pay gap, considerably smaller than say occupation
and industry effects, though they appear to modestly contribute to these differences.

2- Provide feedback on the following text which was extracted from a paper on assortative
mating and inequality. I have added few comments so you can have a general idea of
what I am looking for.

Educational Assortative Mating and Income Inequality in Canada
Introduction and literature review
For as long as we can remember, humans have been known to engage socially and
romantically with one another. One of the ways in which these human relationships
have been explored is through examination of similarities between partners, whether it
be status, wealth, income or any other characteristic. In the case where the
matchmaking characteristic is education based highest level of education attained
this is referred to as educational assortative mating.
Assortative mating is the phenomenon of selecting a partner based on the similarity of
specific socioeconomic variables, such as education, wealth or occupation. Despite
varying trends throughout time, evidence of positive assortative mating at all levels of
education have been observed in certain developed countries, such is the case in both
Norway and the United States, where studies have found this to be more prevalent
among the low educated, but less so among college graduates (Eika et al, 2014).
However, the literature is limited in the sense that the studies have generally only
observed high school and college graduates (Western, Bloome, and Percheski, 2008).
This trend of increasing assortative mating is supported by two empirical facts.
Firstly, the proportion of couples who share the same level of education has been
growing steadily since the early 20th century (Mare, 2016). Secondly, there has also
been a rise in household income inequality in the same time period (Western et al,
2008). Assortative mating may appear to be more natural compared to non-assortative
mating, however there is evidence that it might be one of the factors behind the
increasing income inequality in several developed countries, such the United States and
Switzerland over the past few decades (Kuhn & Ravazzini, 2017; Breen & Andersen,
2012; Mare, 2015).
Earnings inequality is of relevance because it creates a societal divide where the
rich become richer and the poor become poorer. This is evident in the data from the
United States that shows that the probability that a college graduate will marry
someone with a college degree increased by 120% between 1980 and 2007, while the
Gini coefficient (income inequality index) in household income among married couples
increased by 21% over the same period (Greenwood et al, 2014)
Furthermore, income inequality leads to the disappearance of the middle class
over time, by causing a decrease in consumer spending. Between 1998 and 2013 in the
United States for example, consumer spending went down by 3% causing the middle
class to shrink, hurting the economy as a result (Summers, 2016). One of the major
findings from another study on income inequality was that there was increasing income
inequality from 1979 to 1989 (Western et al, 2008). This was been attributed to the fact
that the wages of male college graduates in the United States increased by 66%, and
that of female graduates by 55%. This increase in wages reflected the increased demand
for skilled workers during that period.
Our study takes a look at the relationship between educational assortative
mating and income inequality in Canada, analysing Canadian data to determine the
degree to which these two variables are correlated, and whether increasing assortative
mating causes growth in income inequality over time, at both the national and
provincial levels. This is similar to studies conducted in Denmark (Breen & Anderson,
2012), where in order to examine whether there is a connection between educational
assortative mating and income inequality, Theil and Gini indices were used.
Counterintuitively in this study, it was found that although income inequality went up,
educational homogamy went down. These results are in contrast to other studies
linking assortative mating to income inequality (Kuhn & Ravazzini, 2017; Mare, 2015).

3- The following paragraphs were taken from a paper published by John Cochrane in one
of the top journals in economics. What we will do in this exercise is to try to check whether Cochrane followed the tips and recommendations he mentioned in his guide.
Here is an example:

The author used the active voice.
Example: I describe insurance, This lump sum allows him or her, ..

Time-Consistent Health Insurance

Abstract
Currently available health insurance contracts often fail to insure long-term illnesses:
sick people can suffer large increases in premiums or denial of coverage. I describe
insurance contracts that solve this problem. Their key feature is a severance payment.
A person who is diagnosed with a long-term illness and whose premiums are
increased receives a lump sum equal to the increased present value of premiums. This
lump sum allows him or her to pay the higher premiums required by any insurer.
People are not tied to a particular insurer or a group, and the improvement is free:
insurance companies can operate at zero economic prots, and consumers can pay
exactly the same premium they do with standard contracts.

Introduction
Currently available health insurance contracts do not fully insure many long-term
illnesses, such as AIDS, cancer, senile dementia, heart disease, or organ failure. Many
people who get such diseases face ruinous increases in premiums. Others lose their
health insurance by losing their job or their spouse or by exceeding a lifetime cap on
benets. Some are bankrupted by health expenses; some are unable to get further
medical care. Many other kinds of insurance do not cover longterm risks in the
same way, for example medical malpractice and product liability insurance. The
absence of effective long-term health insurance is perhaps the most important issue
driving health care regulation proposals, including the Clinton plan and congressional
proposals. To the voting, insured, middle class, the plans offer health insurance that
cant be taken away. This absence is also a central motivation for plans offered by
academics (see Enthoven and Kronick 1989, pp. 3435; Himmelstein et a1. 1989;
Pauly et a1. 1991, pp. 1415; and esp. Diamond 1992, pp. 123839).
Neither the authors of health regulation plans nor their critics have focused on the
standard question for a proposed regulation: What, precisely, is the market failure? Or
is the absence of effective long-term health insurance due instead to regulation or
poor court enforcement and ex post reinterpretation of long-term contracts? Plan
authors typically just assume that markets cannot provide long-term health insurance,
or make anecdotal reference to textbook asymmetric information stories. Critics have
focused on the distortionary side effects of the plans and their nancing provisions
(see, e.g., the journal of Economic Perspectives Health Care Reform symposium;
Newhouse 1994; Cutler 1994; Aaron 1994; Pauly 1994; Zeckhauser 1994; Diamond
1994; Poterba 1994). But these and other critics have not answered the planners
central challenge: How can long-term insurance be provided without intrusive and
distorting regulation?
Here, I try to answer this question. I show why current health insurance contracts
cannot provide long-term insurance in a competitive environment. I describe time-
consistent contracts that can provide long-term insurance, and I discuss how time-
consistent contracts might be implemented in practice. I anticipate some objections,
and I offer an explanation for the fact that they have not already been implemented.
The bottom line of the analysis is that markets can provide long-term health
insurance, and deregulation is the likely policy route to achieve it.