regressikynnysmalli

A regressikynnysmalli, which translates to "regression threshold model" in English, is a statistical concept used in regression analysis. It is a type of regression model that incorporates a threshold effect. This means that the relationship between an independent variable and a dependent variable is not assumed to be linear or smooth across the entire range of the independent variable. Instead, the model posits that there is a specific value, or threshold, for the independent variable. Changes in the dependent variable are assumed to occur at different rates or in different ways before and after this threshold is crossed.

For instance, consider the relationship between fertilizer application and crop yield. Up to a certain point, increasing fertilizer might lead to a proportional increase in yield. However, beyond a certain threshold, additional fertilizer might have a diminishing effect or even become detrimental. A regressikynnysmalli would be suitable for capturing this kind of non-linear, piecewise relationship. The model typically estimates the threshold value and the different regression coefficients for the segments of the independent variable on either side of that threshold. This allows for a more accurate representation of phenomena where a critical point exists, beyond which the dynamics of the relationship change. Such models are valuable in fields like economics, environmental science, and biology where threshold effects are common.