Abstract
There is a campaign afoot to pass the Paycheck Fairness Act. It would strengthen the Equal Pay Act of 1963 in an effort to address the pay gap between the earnings of men and women. The proposal is premised on the claim that women earn about 77% of what men earn. This article finds that when we control for hours worked, that number is much higher. In addition, there are important differences among the states. If we were to control for additional factors, we would find that the pay gap is gone. Indeed, women on average may now earn more than men. The considerable progress that has been made in this area is due much more to the operation of Title VII of the Civil Rights Act of 1964 and Executive Order 11246 of 1965 than to the Equal Pay Act.
An earlier article 1 examined the pay-equity debate from the passage of the civil rights legislation of the 1960s and the campaign mounted by the National Organization for Women and others to attain pay equity commencing about 1979. As a result of these efforts and the impact of the historic increase in the labor force participation rate (LFPR) of women (and the attending decline in that of men), women’s gross unadjusted annual earnings went from 60.2% of men’s in 1980 to 77.0% in 2011. In 2012, it fell to 76.5%. The 77% figure has been adopted by women’s groups, government agencies and sympathetic elected officials including President Obama, just as the “59-cent dollar” had been adopted in the 1980s. Since then, the campaign to improve women’s earnings relative to those of men has morphed from “comparable worth” to “pay equity” to the “pay gap.” Today, “pay equity” and “pay gap” are often used interchangeably. The term “comparable worth” has virtually disappeared.
The source of the 77%, figure representing a 23% pay gap, is the U.S. Census Bureau. It is based on annual earnings of full-time year-round workers age 15 and over. 2 The Department of Labor’s (DOL) Bureau of Labor Statistics (BLS) reports similar data for age 16 and older. As presented in Table 1, the BLS data are somewhat higher: 82.2% in 2011 dropping to 80.9% in 2012. Both data series show that the pay gap has improved significantly over the years.
Women’s Earnings as a Percentage of Men’s Earnings, Selected Years, 1960 to 2012.
Calculated by the author.
Source. U.S. Department of Commerce. Census Bureau. Table P-40. Retrieved from www.census.gov. U.S. Department of Labor. Bureau of Labor Statistics. Highlights of women’s earnings in 2012. Report 1045, October 2013. Table 12, p. 54. Retrieved from www.bls.gov.
The pay gap is women’s earnings as a percentage of men’s subtracted from 100. Thus, the nationwide pay gap in 2012 was either 23.5% according to the Census Bureau or 19.1% according to the BLS. Both measures are misleading. They are nationwide annual measures that do not account for hours worked per week, weeks worked per year, educational attainment, college majors and specialties (options) within those majors, physical demands, hazardous and unpleasant working conditions and employee preference. Nor do they account for important differences among the states.
This article examines women’s earnings as a percentage of men’s (or the pay gap) based on weekly earnings of full-time year-round workers. It also contains a discussion of employees paid on an hourly basis. When adjusted for hours worked per week, both the national and state-specific pay data, the pay gap narrows appreciably. Surely, no knowledgeable person would argue that women on average should earn the same as men on average while working fewer hours.
If we were to control for factors other than hours worked, it would show that women on average earn more than men throughout much of the economy and, in the not too distant future, that will be the case nationwide. Policy makers should take this into account before enacting legislation to solve a problem that has already been solved.
We will also examine recent efforts to address the putative pay gap issue with particular attention to the proposed Paycheck Fairness Act and the recent Executive Order 13665.
The Law
The bedrock of the civil rights law in employment is the Equal Pay Act of 1963 (EPA), Title VII of the Civil Rights Act of 1964 (CRA) and Executive Order 11246 issued in 1965. The EPA had its 50th birthday in 2013, the CRA in 2014 and EO 11246 in 2015.
The EPA requires equal pay for substantially equal work requiring the same skill, effort, responsibility and performed under the same working conditions. The so-called “employer defenses” may justify pay differences between men and women if based on a bona fide seniority or merit system, differences in quantity and quality of work, different locations or any factor other than sex. While these measures appear reasonable on their face, it may be argued that the defenses have hobbled the effectiveness of the EPA.
The Civil Rights Act of 1964 is the big one. It created the Equal Employment Opportunity Commission (EEOC). Title VII of the CRA applies to employment: everything from recruitment and selection to training and development to promotion and termination. In regard to pay, Section 703(h) of the Act (once known as the Bennett Amendment) limits the CRA to the provisions of the Equal Pay Act, including the employer defenses.
Originally, the EPA was enforced by the Department of Labor (DOL) because it was an amendment to the Fair Labor Standards Act (FLSA). In 1978, enforcement was transferred to the EEOC and the Department of Justice (DOJ). This was appropriate. The EEOC’s main function is to fight discrimination. Also, pay discrimination cases often intertwine with other types of employment discrimination.
An Executive Order is an order from the President to the Executive Branch of the U.S. government telling it to do something. Part II of EO 11246 requires that federal contractors with 50 or more employees agree not to discriminate on the basis of race, color, religion, sex or national origin. Part I similarly applies to state and local governments. Since almost all large employers are federal contractors or subcontractors and all state and most local governments receive federal grants, the application of the EO is very far reaching. EO 11246 is enforced by the DOL’s Office of Federal Contract Compliance Programs (OFCCP).
Labor Force Participation and Composition
As reported in Table 2, the total labor force participation rate grew from 60.4% in 1970 to 67.1% in 2000. The increase contributed significantly to the substantial growth of the U.S. economy of the 1980s and 1990s. Total LFPR subsequently fell to 63.7% as of 2012. Whether this was a result of the recessions of 2001 and 2008 or a contributing factor is an interesting question. It may be both.
Labor Force Participation Rates and Composition, Selected Years, 1970 to 2012.
Calculated by the author.
Note. Census data are for median full-time year-round workers 15 years and older. BLS data are for same 16 years and older.
Source. For labor force participation rates and composition: U.S. Department of Labor, Bureau of Labor Statistics. Women in the labor force: A databook. May 2014. Tables 1 and 2, pp. 9-14. For earnings (Census Bureau): U.S. Census Bureau. Current Population Survey. Annual Social and Economic Survey. Table P-40. For earnings and weeks worked (BLS): Bureau of Labor Statistics. Highlights of women’s earnings in 2012. October 2013. Report 1045, Tables 13 and 22, pp. 55 and 78.
During the same period, LFPR of women increased dramatically from 43.3% in 1970 to 59.9% in 2000 (down from 60.0% in 1999). It declined to 57.7% in 2012. This accounts for the growth and subsequent decline of the total LFPR. Meanwhile, the LFPR of men shrank from 79.8% in 1970 to 70.2% in 2012. This may be due in part to the growth in retirement income programs.
As a result of this “twist” in the LFPR of men and women, the composition of the labor force went from 61.9% male and 38.1% female in 1970 to 53.1% male and 46.9% female in 2012 (Table 2). That is revolutionary. The trend will likely continue in the years ahead.
Some of these terms may be confusing. The civilian labor force (CLF) includes all nonmilitary and noninstitutionalized individuals, 16 years of age or older, who work or actively seek work. The LFPR is the number of people in the CLF divided by the civilian noninstitutional population (CNP). The LFPR of men (or women) is the number of men (or women) in the CLF divided by the number of men (or women) in the CNP. The composition of the labor force is the number of men (or women) in the CLF divided by the total CLF.
This restructuring of the labor force of the United States underlies the historic progress that women have made at work. Not only are there many more women working outside of the home, they are also engaged in a wide array of positions of responsibility and authority in a host of occupations and professions throughout the economy. While much of the gain in women’s pay is credited to the civil rights legislation and to the efforts of the women’s movement, one cannot help but wonder if it would not have occurred as a result of the underlying demographic changes and market forces.
A Word of Caution
In the social sciences, we understand things largely by comparing them with other things, either longitudinally or cross-sectionally. Benchmarking is a variant of cross-sectional analysis. Knowing the LFPR of Hispanic women in 2005 is meaningless until it is compared to that of Hispanic men or to women of other ethnicities or to previous or subsequent time periods or to some target or benchmark number. To do that we need comparable statistics.
Mark Twain is often quoted to have said, “There are lies, damn lies and statistics.” That may be a humorous overstatement; but there is some truth in it. Data, especially survey data, must be approached with caution. Surveys are based on samples. The smaller the sample size, the greater the standard error. The wording of survey questions and the number and wording of allowed responses influence results. Definitions are important, especially when comparing different data sources.
A researcher must make judgments on the appropriateness of one time period over another, which years to report and which data series to use and compare. These decisions may be influenced by the message he or she intends to convey.
Most data on women’s earnings as a percentage of men’s originates in the Current Population Survey (CPS) conducted by the U.S. Bureau of Labor Statistics (BLS) for the Census Bureau. The BLS surveys a sample of 60,000 households each month (during a reference week that includes the 12th) in considerable detail. This generates a host of data that are then published by the BLS, Census Bureau and other government agencies, such as the DOL’s Women’s Bureau. The data are accessed and “packaged” by various organizations for the benefit of their constituencies. The BLS also provides “establishment” (employer) data but in less detail.
Pay data are reported on an annual and on a weekly basis. They are also available on an hourly basis for those paid hourly. The Census Bureau and the DOL’s Women’s Bureau tend to favor annual pay data (annual earnings of full-time employed women divided by that of men). The term “full-time” may be misleading. It refers to employees who usually work 35 or more hours per week. This masks the fact that men employed full-time work more hours in the week and more weeks in the year than do women. A better measure is weekly, or even hourly, earnings.
The Wage Gap for Hourly Paid Employees
Table 3 displays data on the experience of workers paid by the hour. While it excludes the millions of salaried employees, it is a “cleaner” metric as it nullifies the differences in hours worked per week or weeks worked per year.
Women’s Earnings as a Percentage of Men’s for Workers Paid Hourly, Selected Years, 1979 to 2011.
Source. U.S. Department of Labor, Bureau of Labor Statistics. Highlights of women’s earnings in 2012. Report 1038, October 2013. Table 15, p. 57.
For the workforce as a whole (age 16 and older), women’s hourly earnings as a percentage of men’s grew from 64.1% in 1979 to 86.4% in 2012. That is significantly better than the 76.5% from the Census Bureau.
Consider also in Table 3 that for the 16 to 24 year age group, there is very little pay gap. For older workers (age 25 to 64), women’s pay as a percentage of men’s is 86.8% overall. Observe how it declines from 91.5% for the 25 to 34 year olds to 83.1% for the 55 to 64 age group. This reflects the large (but shrinking) number of women who withdraw from the labor force to raise children. Women’s hourly pay as a percentage of men’s then jumps to 90.9% for those 65 and over, down from 97.8% in 2005.
Hour Worked per Week and the Weekly Pay Gap
Full-time year-round employed men work more hours per week than do women. As shown in Table 4, in 2012 men worked an average of 40.8 hours per week while women worked 35.8 hours, a 5.0-hour difference. That is down from 41.7 hours and 34.1 hours, respectively, in 1979, a 7.6-hour difference. Five hours more per week is the equivalent of 31 additional 8-hour workdays or more than 6 workweeks per year.
Median Weekly Usual Hourly Earnings of Men and Women Employed Full-Time Adjusted for Hours Worked per Week.
Calculated by the author.
Source. U.S. Department of Labor, Bureau of Labor Statistics. Highlights of women’s earnings in 2012. October 2013. Report 1045. Weekly earnings: Table 23, pp. 77-79. Hours: Bureau of Labor Statistics. Women in the labor force: A databook. May 2014. Table 21, p. 79.
When weekly earnings for men and women are divided by their respective hours worked per week, we get an imputed hourly pay rate. If we then divide the female imputed hourly rate by the male rate, we get women’s hourly pay as a percentage of men’s. That number has increased from 76.3% in 1979 to 92.2% in 2012 (down from 93.8% in 2011). That is considerably higher than the unadjusted 77.0% based on annual Census Bureau data or the 82.2% of the BLS data. By this measure, the 2012 pay gap was 7.8%.
If we were to control for the other factors mentioned above, the wage gap would be smaller, or even negative. That is, women on average may now be earning more than men on average.
Pay Data Adjusted for Hours Worked Among the States
The pay equity debate has been based on national data. There is some logic to this. The main player in addressing employment discrimination is the federal government. While many states are also active in this area, those efforts vary considerably. National data, however, mask major differences among the states. They often do. Proposed federal legislation and misdirected enforcement efforts directed at solving the national pay-gap problem could result in unintended harm and misallocated resources.
Table 5 adjusts women’s earnings as a percentage of men’s for hours worked per week in the 10 largest states in order of the size of the civilian labor force. That is a good sample of the whole. In 2012, California led the nation with an unadjusted rate of 86.0% (down from 89.9% in 2011). Florida, Ohio and New York were not far behind. The lowest (worst) rate among the “big 10” states was Georgia with an unadjusted rate of 76.4%. The 10-state average was 81.2%.
Women’s Pay as a Percentage of Men’s for Persons Who Usually Work Fulltime Adjusted for Hours Worked in 10 Largest States by Size of Civilian Labor Force, 2012.
Calculated by the author. Columns may not sum and rows may not compute due to rounding.
Source. U.S. Department of Labor, Bureau of Labor Statistics. For median weekly earnings: Highlights of women’s earnings in 2012. October 2013. Report 1045. Table 3, pp. 36-37. For hours worked per week: Geographic profile of employment and unemployment, 2012. September 2013. Bulletin 2774. Table 22, pp. 149-151. Retrieved from www.bls.gov.
When we adjust the women’s pay as a percentage of men’s for hours worked per week, we get a different picture. The range in 2012 was from 89.8% in California to 81.8% in Georgia. The 10-state mean was 86.9%. Adjusting for the difference in the number of hours worked per week in the “big-10” states greatly changes things.
Table 6 reports the results of the same adjustment applied to the 10 highest (best) states. Arizona tops the unadjusted list 86.8% with California a close second. When we adjust for hours worked, Arizona and Nebraska tie for first place at 90.9% and Arkansas comes in second at 90.3%. The remaining “high-10” states are not far behind. The 10-state average is 89.6%. If we were to adjust for the other factor mentioned above, we would find that women earn more than men in these and in other states as well.
Women’s Pay as a Percent of Men’s for Persons Who Usually Work Fulltime Adjusted for Hours Worked per Week in 10 States with Highest Percentage, 2012.
Calculated by the author. Columns may not sum and rows may not compute due to rounding.
Source. U.S. Department of Labor, Bureau of Labor Statistics. For median weekly earnings: Highlights of women’s earnings in 2012. October 2013. Report 1045. Table 3, pp. 36-37. For hours worked per week: Geographic profile of employment and unemployment, 2012. September 2013. Bulletin 2774. Table 22, pp. 149-151. Retrieved from www.bls.gov.
Table 7 reports similar data for the 10 lowest (worst) states. The unadjusted range was from 65.5% in Wyoming to 77.0% in Connecticut. The 10-state mean was 74.1%. When adjusted for hours worked, the range was 73.8% in Wyoming to 83.2% in Mississippi. The 10-state mean was 80.6%.
Women’s Pay as a Percentage of Men’s for Persons Who Usually Work Full-Time Adjusted for Hours Worked per Week in 10 States With Lowest Percentage, 2012.
Calculated by the author. Columns may not sum and rows may not compute due to rounding.
Source. U.S. Department of Labor, Bureau of Labor Statistics. For median weekly earnings: Highlights of women’s earnings in 2012. October 2013. Report 1045. Table 3, pp. 36-37. For hours worked per week: Geographic profile of employment and unemployment, 2012. September 2013. Bulletin 2774. Table 22, pp. 149-151. Retrieved from www.bls.gov.
Among the 50 states, differences in hours worked per week between men and women vary substantially from 1.8 in California to 4.8 in Louisiana. While there are significant differences among the states in both unadjusted and adjusted rates of women’s pay relative to that of men, those differences exist against a backdrop of impressive improvement by any measure. That will likely continue.
What Happened?
The impact of the EPA was limited by its central concept of “equal pay for equal work” and further constrained by its employer defenses. Title VII of the Civil Rights Act was limited to the provisions of the EPA by its Section 703(h). And yet, women’s earnings as a percentage of men’s have increased appreciably and the pay gap has shrunk, especially when earnings are adjusted for hours worked. If adjusted for weeks worked per year, educational attainment, college majors and specialties (options) within those majors, physical demands and hazardous and unpleasant working conditions, we would likely find that women on average now earn more than men on average. The pay gap is gone. How did that happen?
Section 703(h) did not restrict the CRA in areas other than pay. The CRA, with its broader stronger powers and EEOC and DOJ enforcement, fully applied to recruitment and selection, training and development, promotion and transfer and the remainder of the employment function. EO 11246 required that federal contractors and grant recipients take “affirmative action” (origin of the term) to implement the requirements of Title VII.
Table 8 reports charges filed with the EEOC by major category for selected years 1992 to 2012. Charges filed under the EPA average just over 1% of total cases filed. And, as reported in Table 9, less than a quarter of the EPA cases resolved are resolved in favor of the charging party. In contrast, charges filed for other sex-discrimination issues under Title VII are quite large, exceeded only by racial discrimination charges, and not by much (Table 8). Clearly, the EPA was not the driving force behind the improvement in women’s pay as a percentage of men’s. Nor was the CRA directly responsible since it was limited to the provisions of the EPA by Section 703(h). What did work, however, was the effective application of Title VII to other (nonpay) sex discriminatory practices.
Number and Percentage of Charges Filed With the EEOC by Major Category, Selected Years, 1992 to 2012.
Note. Columns do not sum due to omission of a number of categories.
Source. U.S. Equal Employment Opportunity Commission. Charge statistics. Retrieved from www.eeoc.gov.
Equal Pay Act Charges and Case Resolutions, Selected Years, 1992 to 2013.
In favor of charging party. Percentage values calculated by the author.
Source. U.S. Equal Employment Opportunity Commission. Equal Pay Act charges (includes concurrent charges with Title VII, ADEA and ADA). Retrieved from www.eeoc.gov.
Millions of women opted to enter, reenter and remain in the labor force out of financial necessity, to enhance family income and/or to enrich their lives with a career. The result was the enormous increase in the labor force participation rate of women discussed above and captured in Table 2. In addition, as millions of women chose to pursue higher education and other training opportunities beginning in the 1960s, many elected college majors and specializations once thought the preserve of men. Aided by the affirmative action requirements of EO 11246, an increasing number of women moved into positions of influence and responsibility in organizations and institutions throughout the economy. It is hard to imagine that such women serving as executives and administrators, human resources and compensation managers, elected officials on city councils, state legislators and members of Congress and the judiciary (including the U.S. Supreme Court) would condone continued pay discrimination. They would not. They did not.
Recent Efforts to Solve the Pay-Gap Problem
Notwithstanding the availability of better weekly data, the annual 77% (as of 2011) figure seems to have taken root in the ongoing debate over pay equity. It is often repeated by women’s groups and their supporters, including President Obama. The fact that women’s earnings as a percentage of men’s on an annual unadjusted basis remained stuck from 2001 to 2011 is no doubt part of it. Weekly unadjusted data continued to improve, albeit more slowly than in the past. That may be due to the impact of the recessions of 2001 and 2008.
There has been a resurgence of interest in the pay gap and growing pressure for the federal government to do something about it. In addition to the usual chorus from women’s organizations, the Obama Administration has added its considerable voice to the campaign. The first substantive bill signed into law by the President was the Lilly Ledbetter Fair Pay Act (P.L. 111-2). It dealt with the statute of limitations in regard to pay under the Civil Rights Act of 1964. The Fair Pay Act effectively reversed the Supreme Court decision in Ledbetter v. Goodyear Tire and Rubber Co. The Court had held that Ledbetter could not file a claim for pay discrimination because the employer’s decision had been made more than 6 months before. The Act established that a charge of pay discrimination could be filed within 180 days of the receipt of a discriminatory paycheck. This was a huge increase of the statute of limitations.
In January 2010, the Obama Administration established the National Equal Pay Task Force (Task Force) consisting of representatives from the EEOC, DOJ, DOL and the Office of Personnel Management (OPM). The purpose of the Task Force is to identify persistent causes of pay discrimination and to make recommendations to address them. One of the recommendations the Task Force has made is for the Administration to work with Congress for the passage of the proposed Paycheck Fairness Act (S. 84, now 2119, and H.R. 377).
The proposed legislation would prohibit penalizing employees for sharing salary information with coworkers, allow compensatory and punitive damages (currently the EPA allows only back pay awards and liquidated damages) and facilitate class action suits by applying the Federal Rules of Civil Procedure (FRCP) to equal-pay proceedings. The EPA was enacted before the FRCP was adopted and requires that plaintiffs “opt in” to a class action law suit. The FRCP would require (allow) that they “opt out.” The proposal would also weaken the EPA’s employer defenses by repealing the “any factor other than sex” provision. 3
The Paycheck Fairness Act was first introduced in 2007. It was approved by the House in 2009 but not acted upon by the Senate. The proposal was reintroduced in 2011 at the Obama Administration’s urging but was rejected again. Efforts to pass the Paycheck Fairness Act continue. As recently as September 10, 2014, 73 senators of both parties voted to have a debate on the proposal. Five days later the Senate fell 6 votes short of the 60 needed to prevent a filibuster and take a vote. Majority Leader Reed changed his vote to “no” to allow the bill to be resubmitted, as it no doubt will be.
Executive Order 13665
On September 17, 2014, the OFCCP announced in the Federal Register a Notice of Proposed Rule Making (NPRM) to prohibit pay secrecy policies and proscribe employer retaliation when such policies are violated for federal contractors and subcontractors. The Order had been signed by President Obama on April 8, 2014. Whether this measure represents a substantive improvement or is merely symbolic is an interesting question.
Pay secrecy is widespread. However, it is usually the result of workplace culture rather than official corporate policy. Moreover, in this era of job postings (which usually include salary ranges), employees have a pretty good idea how much their colleagues earn except, perhaps, at the upper levels of management. Federal contractors have Affirmative Action Plans that require internal job postings. If there is a labor agreement they also know.
For an employer to retaliate against employees who share pay information would be pretty shabby employee relations. In most situations, it would be counterproductive.
In my opinion, EO 13665 is largely symbolic. It will not do much harm, but it would not do much good either. It is interesting that the Obama Administration did not include the other provisions of the proposed Paycheck Fairness Act. Why not?
Should Section 703(h) Be Repealed?
A logical question to ask at this point is, “Why not just repeal Section 703(h)?” After all, that is what limits Title VII in regard to pay to the provisions of the EPA. In my opinion, we should not. Congress knew what it was doing when it approved 703(h).
When it comes to wage and salary determination, we should be very careful not to interfere with market forces any more than necessary. While not perfect, a competitive labor market is the best way to determine wages and salaries in a way that effectively allocates human capital throughout the economy.
It is one thing to require employers to do the right thing in regard to other (especially racial) forms of discrimination. The cost imposed on employers can be mitigated by requiring that skills and ability be equal and allowing for “bona fide occupational qualifications.” To set pay rates for men and women by EEOC and DOJ proceedings or judicial fiat is more dangerous, especially if, as argued above, the egregious gender-based pay discrimination has already been effectively addressed.
Conclusion
Without question, women have been discriminated against in employment and in other areas of life throughout history and throughout the world. It has been only recently that meaningful efforts have been taken to ameliorate that. Pay equity has been a part of that effort. In the United States (and in other advanced countries) that has taken the form of laws prohibiting pay discrimination.
The Equal Pay Act of 1963 did not have much of an impact due to its central concept (equal pay for equal work) and its employer defenses. Similarly, the Civil Rights Act of 1964 did not directly affect pay to a significant extent because Section 703(h) limited the CRA to the provisions of the EPA in regard to pay. What did work, however, was the nonpay requirements of Title VII coupled with the affirmative action mandate of EO 11246 and the huge increase in the LFPR of women (and the decline in that of men) and the consequent impact on the composition of the labor force.
These improvements have been greater in some states than in others. In fact, if differences in hours worked, physical demands and unpleasantness of the job, choice of college major and other objective factors were taken into account, we would find that the “unexplainable” pay gap has disappeared.
Meanwhile, the women’s movement and the Obama Administration are determined to solve a problem that no longer exists; at least not as a systematic nationwide sense. The perception that the pay gap is a large and persistent problem is based on dated and misunderstood nationwide data unadjusted for hours worked per week and various other objective factors.
None of this is to imply that the EEOC and DOJ and the courts should lessen their efforts to redress pay discrimination where found. There will always be a need to enforce nondiscrimination laws; just as there is still a need to continue to police wage and hour law 75 years after the passage of the Fair Labor Standards Act. Nor is it to imply that women do not have legitimate grievances in other area of employment and elsewhere: family matters, domestic violence, reproductive rights, health benefits and retirement income. They do. But these problems should be dealt with separately and not used to complicate the pay-gap issue.
Footnotes
Declaration of Conflicting Interests
The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author received no financial support for the research, authorship, and/or publication of this article.