Conflict of interest

A conflict of interest is a situation in which a person or organization experiences conflicting goals. Sometimes this can lead to ethical and professional issues.

Many conflicts of interest can be boiled down to "what's personally good for me isn't good for my employer" or "I am loyal to two groups, and what is good for one is bad for another".

Types
Here are a few examples of conflicts of interests:
 * Self-dealing involves using the employer's resources for personal gain. In the case of charities, this can involve purchasing products or services from companies owned by members of the board of directors or their families, or even directly benefiting the members of the board beyond their salaries.
 * Nepotism involves hiring or giving favors to family members or close friends because of personal ties instead of merit.
 * Gifts or bribes given to influence someone in power.
 * Pump and dump, a process by which a stock broker or major shareholder spreads rumors to increase or decrease the value of a certain stock for financial reasons.

Legalities and rules
While some conflicts of interest are technically not illegal (like recommending your best friend's business to an employer), other forms are more serious and can warrant fines or prison sentences.

Public sector

 * Judges must recuse themselves if they have a conflict of interest (such as a personal relationship with someone in the case).

Private sector

 * During hiring, a company may ask an applicant if they have any family members in the company. If so, the family member won't be included in the decision of whether to hire the applicant.
 * Many companies have rules about workplace dating, especially between a manager and an employee that they manage.
 * Insider trading is illegal.

Academics

 * Researchers are expected to declare in publications any potential conflicts of interest with their research, particularly for sources of funding that may benefit from research outcomes.

Notable examples

 * Anti-vaxx "scientist" Andrew Wakefield published a fraudulent paper claiming that the MMR vaccine could cause autism. He wanted to patent and profit from his own formulation of the MMR vaccine, and lawyers were paying him to make these claims in court.
 * Brian Hooker, a person already pursuing a case in the Vaccine Court involving his child where he believed that the MMR vaccine gave his child autism, attempted a "reanalysis" of a DeStefano et al. paper to try to prove vaccines can cause autism. This is part of the whole CDC whistleblower hullabaloo.
 * According to the Citizens for Responsibility and Ethics in Washington (CREW), then-President Donald Trump had over 2,000 conflicts of interest in summer 2019. This included political events and foreign dignitary visits at his properties. As of February 2020, the number is nearing 3,000.
 * The Non-GMO Project has partnered with Cargill to certify Cargill products as GMO-free, raising concerns about accuracy.