| Type of variables | Variables | Name of variables | Measurement |
| Dependent Variable |
| Unrelated M&As | If company i in industry p makes unrelated M&As in year t, take the value of 1; if not, 0 |
| Explanatory variable |
| Mathematical expectation of probability for unrelated M&As in the same industry | The mathematical expectation of probability for unrelated M&As made by companies other than company i in industry P in year t − 1 |
| Control variables | Related | M&As of related parties | Related parties make M&As, take the value of 1; if not, 0 |
| Dual | Duality | Duality of chairman and general manager, take the value of 1; if not, 0 | |
| Property | Nature of property | State-owned enterprise, take the value of 1; if not, 0 | |
| First | The shareholding ratio of first majority shareholder | Shareholding quantity of first majority shareholder/total number of shares | |
| Lndep | Proportion of independent directors | Number of independent directors/the number of board members | |
| Board | Board size | The total number of board members | |
| ESH | Management shareholding | Management shareholding quantity/total number of shares | |
| Overcon | The overconfidence degree of executives | Remuneration of top three executives/total remuneration of executives | |
| Cash | Cash stock ratio | Cash stock/total assets | |
| Intang | Intangible assets ratio | Intangible assets/total assets | |
| Tobinq | Tobin’s Q | Market value/replacement cost | |
| OCF | Operating cash flow ratio | Operating net flows/total assets | |
| Size | Asset size | The natural logarithm of total assets | |
| ROA | Total asset and net profit ratio | Net profit/Total assets | |
| Lev | Asset-liability ratio | Liabilities/Total assets | |
| Growth | Growth rate of operation revenue | (operation revenue in current year-operation revenue in the previous year)/operation revenue in the previous year | |
| Accrual | Discretionary accruals of company | Manipulated accrual profit calculated with the modified Jones model/total assets | |
| FC | Financing restraint level | KZ index | |
| Bedrivers | The diversification level before M&As | 1-Herfindahl index |