Data in Brief

This article provides in-depth data on gender diversity, corporate governance practices and speciﬁc ﬁrm factors. The study compiles panel data for all publicly listed companies in the United States, featured in the S&P index from 20 0 0 to 2018, except for ﬁnancial and utilities ﬁrms. The data set includes variables regarding gender diversity, board characteristics, ﬁrm performance, and other crucial factors. The data was extracted from the annual reports of each ﬁrm us-ing Compustat and BoardEX databases. Researchers can apply the data in assessing the impact of appointing female directors on the value of a ﬁrm through event studies. Moreover, the dataset can help address endogeneity issues, enabling researchers to control for potential confounding variables and draw more accurate conclusions.


Value of the Data
• This dataset provides researchers with the opportunity to analyze the correlation between the presence of female directors and a company's financial performance.• The dataset offers a comprehensive view of gender diversity in the corporate world, enabling a better understanding of the global status of female directors and trends in their appointment to boards over time.
• By providing variables related to board characteristics, firm performance, and other relevant factors, the dataset can assist in addressing endogeneity issues, allowing researchers to control for potential confounding variables and draw more accurate conclusions.• The dataset can also be utilized to evaluate the signalling effects of the appointment of female directors on firm value through event studies.

Data Description
The dataset provides insights into corporate governance and finance.It enables researchers to examine gender diversity in boardrooms, firm performance and characteristics, board composition and independence, and instrumental variables.These factors can help researchers uncover patterns, relationships, and implications for corporate practices and performance [ 4 , 6 ].
This dataset covers all publically listed companies in the United States from 20 0 0 to 2018 which are listed in the S&P index.The starting point of 20 0 0 is due to the minimal data available in the BoardEX database before this time in relation to board directors' information.Compustat is the source of financial data.As previous research indicates, financial and utilities firms are excluded from the sample due to their distinct regulations, which expose their directors to liability risks that non-financial firms are not subject to [ 1 , 7 ].The sample size of non-financial firms amounts to 17,220.Financial variable outliers are adjusted to the 98 % level in accordance with Bharath and Shumway's [3] study.
Table 1 presents a comprehensive description of the variables that are provided in this data article.These variables play a crucial role in examining various aspects of corporate governance, firm performance, and the impact of gender diversity in the boardroom, making them valuable tools for empirical research in business and economics [ 2 , 5 ].
Table 2 displays descriptive statistics for the variables in the dataset, categorized into three main groups: Firm Characteristics, Board Characteristics, and Instrumental Variables.In the Firm Characteristics section, financial and operational indicators are analyzed.It is worth noting that Return on Assets (ROA) has an average of 0.09, indicating that, on average, the firms in the sample generate a 9 % return on their assets.Tobin's Q has an average of 2.05, suggesting that firms typically have a higher market value compared to their book value.Firm size is measured by the natural logarithm of total assets, with an average of 7.36.It seems that firms have moderate

Instruments Male connectedness to female directors
The proportion of male directors on the board who sit on other boards with at least one female director.

Female industry ratio
The proportion of female directors in the same industry based on two-digit code.

Firm visibility (S&P 500)
A dummy variable that takes one if a firm is listed in the S&P 500 and zero otherwise.
capital expenditure, as the capital expenditure variable has an average of 0.05.Research and development expenditure is relatively low, with an average of 0.03.In addition, the average age of firms is about 32 years, and the mean firm growth rate is 0.11.The board characteristics section provides insights into the composition of corporate boards.On average, there are approximately 8.90 directors per board, with 6.16 of them being independent directors.Female directors make up around 1.08 positions, accounting for about 11 % of the total directors.The mean age of directors is around 61 years, while directors have an average tenure of 6.53 years.Board independence, measured as the ratio of independent directors, is about 0.68.The board size seems to be relatively stable, with an average of 2.15.A subset of directors holds CPA certificates and master's/PhD degrees, which may be important for board expertise.Within the instrumental variables section, the female industry ratio is around 12 %, indicating that women are not highly represented in the broader industry.Additionally, directors in your sample are also connected to external seats, with an average of 1.50 external seats.

Experimental Design, Materials and Methods
There are 12 variables related to firm characteristics, 15 variables related to board characteristics, 6 variables related to female directors' characteristics and 3 instrumental variables.The data is categorized based on publicly listed non-financial US firms that have complete information available from the Compustat database.This information is then matched with directors' information from BoardEx.
These variables are significant because they can be used to investigate a range of research questions in the fields of corporate governance, finance, economics, and management.Researchers can utilize these variables to study topics such as board diversity, firm performance, governance structures, and external influences.They also allow for the exploration of how factors like gender, firm size, age, and industry dynamics impact corporate behaviour and outcomes.The diversity of these variables creates a variety of research possibilities and can contribute to a deeper understanding of how different factors influence business operations and outcomes.

Table 1
Definition of variables.